Let the duration of each period be x. Period 8 9 Duration of period (in minutes) 45 x Here the number of periods and the duration of periods are in inverse proportion. ∴ 8/9 = x/45 ⇒ xX9 = 8x45 ⇒ x = 8x45/9 = 40 minutes Hence, the duration of each period would be 40 minutes. Class 8 Maths Chapter 11Read more
Let the duration of each period be x.
Period 8 9
Duration of period (in minutes) 45 x
Here the number of periods and the duration of periods are in inverse proportion.
∴ 8/9 = x/45 ⇒ xX9 = 8×45 ⇒ x = 8×45/9 = 40 minutes
Hence, the duration of each period would be 40 minutes.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
(i) Let the number of days be x. Persons 2 1 Days 3 x Here, the number of persons and the number of days are in inverse proportion. ∴ 2/1 = x/3 ⇒ xX1=2x3 ⇒ x=2x3/1 = 6 days (ii) Let the number of persons be x. Persons 2 x Days 3 1 Here, the number of persons and the number of days are in inverse proRead more
(i) Let the number of days be x.
Persons 2 1
Days 3 x
Here, the number of persons and the number of days are in inverse proportion.
∴ 2/1 = x/3 ⇒ xX1=2×3 ⇒ x=2×3/1 = 6 days
(ii) Let the number of persons be x.
Persons 2 x
Days 3 1
Here, the number of persons and the number of days are in inverse proportion.
∴ 2/x = 1/3 ⇒ xX1=2×3 ⇒ x=2×3/1= 6 persons
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Let the number of hours be x. Speed (in km/hr) 60 80 Time (in hours) 2 x Here, the speed of car and time are in inverse proportion. ∴ 60/80 = x/2 ⇒ xX80 = 60x2 ⇒ x= 60x2/80=3/2 = (1)1/2 hrs Hence, the car will take hours (1)1/2 hrs to reach its destination. Class 8 Maths Chapter 11 Exercise 13.2 SolRead more
Let the number of hours be x.
Speed (in km/hr) 60 80
Time (in hours) 2 x
Here, the speed of car and time are in inverse proportion.
∴ 60/80 = x/2 ⇒ xX80 = 60×2 ⇒ x= 60×2/80=3/2 = (1)1/2 hrs
Hence, the car will take hours (1)1/2 hrs to reach its destination.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Let the number of machines required be x. Days 63 54 Machines 42 x Here, the number of machines and the number of days are in inverse proportion. ∴ 63/54 = x/42 ⇒ xX54=63x42 ⇒ x=63x42/54 = 49 Hence, 49 machines would be required. Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answRead more
Let the number of machines required be x.
Days 63 54
Machines 42 x
Here, the number of machines and the number of days are in inverse proportion.
∴ 63/54 = x/42 ⇒ xX54=63×42 ⇒ x=63×42/54 = 49
Hence, 49 machines would be required.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Let the number of boxes be x. No. of bottles in each box 12 20 Boxes 25 x Here the number of bottles and the number of boxes are in inverse proportion. ∴ 12/20 = x/25 ⇒ xX20=12x25 ⇒ x=12x25/20=15 Hence, 15 boxes would be filled. Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answeRead more
Let the number of boxes be x.
No. of bottles in each box 12 20
Boxes 25 x
Here the number of bottles and the number of boxes are in inverse proportion.
∴ 12/20 = x/25 ⇒ xX20=12×25 ⇒ x=12×25/20=15
Hence, 15 boxes would be filled.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Let time taken to complete the job be x. Persons 3 4 Days 4 x Here the number of persons and the number of days are in inverse proportion. ∴ 3/4 = x/4 ⇒ 4Xx=3x4 ⇒ x=3x4/4= 3days Hence, they will complete the job in 3 days. Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answers visRead more
Let time taken to complete the job be x.
Persons 3 4
Days 4 x
Here the number of persons and the number of days are in inverse proportion.
∴ 3/4 = x/4 ⇒ 4Xx=3×4 ⇒ x=3×4/4= 3days
Hence, they will complete the job in 3 days.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Let the number of days be x. Total number of animals = 20 + 10 = 30 Animals 20 30 Days 6 x Here, the number of animals and the number of days are in inverse proportion. ∴ 20/30=x/6 ⇒ 30Xx=20x6 ⇒ x=20x6/30 = 4 Hence, the food will last for four days. Class 8 Maths Chapter 11 Exercise 13.2 Solution inRead more
Let the number of days be x. Total number of animals = 20 + 10 = 30
Animals 20 30
Days 6 x
Here, the number of animals and the number of days are in inverse proportion.
∴ 20/30=x/6 ⇒ 30Xx=20×6 ⇒ x=20×6/30 = 4
Hence, the food will last for four days.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
∵ Each child gets = 5 sweets ∵ 24 children will get 24 x 5 = 120 sweets Total number of sweets = 120 If the number of children is reduced by 4, then children left = 24 – 4 = 20 Now each child will get sweets = 120/20 = 6 sweets Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answerRead more
∵ Each child gets = 5 sweets ∵ 24 children will get 24 x 5 = 120 sweets
Total number of sweets = 120
If the number of children is reduced by 4, then children left = 24 – 4 = 20
Now each child will get sweets = 120/20 = 6 sweets
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Here the number of spokes are increasing and the angle between a pair of consecutive spokes is decreasing. So, it is a inverse proportion and angle at the centre of a circle is 360°. When the number of spokes is 8, then angle between a pair of consecutive spokes = 360°/8 =45° When the number of spokRead more
Here the number of spokes are increasing and the angle between a pair of consecutive
spokes is decreasing. So, it is a inverse proportion and angle at the centre of a circle is 360°.
When the number of spokes is 8,
then angle between a pair of consecutive spokes = 360°/8 =45°
When the number of spokes is 10,
then angle between a pair of consecutive spokes = 360°/10 =36°
When the number of spokes is 12,
then angle between a pair of consecutive spokes = 360°/12 =30°
No. of spokes 4 6 8 10 12
Angle between a pair of consecutive spokes 90° 60° 45° 36° 30°
(i) Yes, the number of spokes and the angles formed between a pair of
consecutive spokes is in inverse proportion.
(ii) When the number of spokes is 15, then angle between a pair of consecutive
spokes = 360°/15 = 24°
(iii) The number of spokes would be needed = 360°/40° = 9°
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
Here number of winners and prize money are in inverse proportion because winners are increasing, prize money is decreasing. When the number of winners are 4, each winner will get = 100000/4 = ₹25,000 When the number of winners are 5, each winner will get = 100000/5= ₹20,000 When the number of winnerRead more
Here number of winners and prize money are in inverse proportion because
winners are increasing, prize money is decreasing.
When the number of winners are 4, each winner will get = 100000/4 = ₹25,000
When the number of winners are 5, each winner will get = 100000/5= ₹20,000
When the number of winners are 8, each winner will get = 100000/8 = ₹12,500
When the number of winners are 10, each winner will get = 100000/10= ₹10,000
When the number of winners are 20, each winner will get = 100000/20 = ₹5,000
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
A school has 8 periods a day each of 45 minutes duration. How long would each period be, if the school has 9 periods a day, assuming the number of school hours to be the same?
Let the duration of each period be x. Period 8 9 Duration of period (in minutes) 45 x Here the number of periods and the duration of periods are in inverse proportion. ∴ 8/9 = x/45 ⇒ xX9 = 8x45 ⇒ x = 8x45/9 = 40 minutes Hence, the duration of each period would be 40 minutes. Class 8 Maths Chapter 11Read more
Let the duration of each period be x.
Period 8 9
Duration of period (in minutes) 45 x
Here the number of periods and the duration of periods are in inverse proportion.
∴ 8/9 = x/45 ⇒ xX9 = 8×45 ⇒ x = 8×45/9 = 40 minutes
Hence, the duration of each period would be 40 minutes.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
Two persons could fit new windows in a house in 3 days. (i) One of the persons fell ill before the work started. How long would the job take now? (ii) How many persons would be needed to fit the windows in one day?
(i) Let the number of days be x. Persons 2 1 Days 3 x Here, the number of persons and the number of days are in inverse proportion. ∴ 2/1 = x/3 ⇒ xX1=2x3 ⇒ x=2x3/1 = 6 days (ii) Let the number of persons be x. Persons 2 x Days 3 1 Here, the number of persons and the number of days are in inverse proRead more
(i) Let the number of days be x.
Persons 2 1
Days 3 x
Here, the number of persons and the number of days are in inverse proportion.
∴ 2/1 = x/3 ⇒ xX1=2×3 ⇒ x=2×3/1 = 6 days
(ii) Let the number of persons be x.
Persons 2 x
Days 3 1
Here, the number of persons and the number of days are in inverse proportion.
∴ 2/x = 1/3 ⇒ xX1=2×3 ⇒ x=2×3/1= 6 persons
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
A car takes 2 hours to reach a destination by travelling at the speed of 60 km/hr. How long will it take when the car travels at the speed of 80 km/hr?
Let the number of hours be x. Speed (in km/hr) 60 80 Time (in hours) 2 x Here, the speed of car and time are in inverse proportion. ∴ 60/80 = x/2 ⇒ xX80 = 60x2 ⇒ x= 60x2/80=3/2 = (1)1/2 hrs Hence, the car will take hours (1)1/2 hrs to reach its destination. Class 8 Maths Chapter 11 Exercise 13.2 SolRead more
Let the number of hours be x.
Speed (in km/hr) 60 80
Time (in hours) 2 x
Here, the speed of car and time are in inverse proportion.
∴ 60/80 = x/2 ⇒ xX80 = 60×2 ⇒ x= 60×2/80=3/2 = (1)1/2 hrs
Hence, the car will take hours (1)1/2 hrs to reach its destination.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
A factory requires 42 machines to produce a given number of articles in 63 days. How many machines would be required to produce the same number of articles in 54 days?
Let the number of machines required be x. Days 63 54 Machines 42 x Here, the number of machines and the number of days are in inverse proportion. ∴ 63/54 = x/42 ⇒ xX54=63x42 ⇒ x=63x42/54 = 49 Hence, 49 machines would be required. Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answRead more
Let the number of machines required be x.
Days 63 54
Machines 42 x
Here, the number of machines and the number of days are in inverse proportion.
∴ 63/54 = x/42 ⇒ xX54=63×42 ⇒ x=63×42/54 = 49
Hence, 49 machines would be required.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
A batch of bottles was packed in 25 boxes with 12 bottles in each box. If the same batch is packed using 20 bottles in each box, how many boxes would be filled?
Let the number of boxes be x. No. of bottles in each box 12 20 Boxes 25 x Here the number of bottles and the number of boxes are in inverse proportion. ∴ 12/20 = x/25 ⇒ xX20=12x25 ⇒ x=12x25/20=15 Hence, 15 boxes would be filled. Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answeRead more
Let the number of boxes be x.
No. of bottles in each box 12 20
Boxes 25 x
Here the number of bottles and the number of boxes are in inverse proportion.
∴ 12/20 = x/25 ⇒ xX20=12×25 ⇒ x=12×25/20=15
Hence, 15 boxes would be filled.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
A contractor estimates that 3 persons could rewire Jasminder’s house in 4 days. If, he uses 4 persons instead of three, how long should they take to complete the job?
Let time taken to complete the job be x. Persons 3 4 Days 4 x Here the number of persons and the number of days are in inverse proportion. ∴ 3/4 = x/4 ⇒ 4Xx=3x4 ⇒ x=3x4/4= 3days Hence, they will complete the job in 3 days. Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answers visRead more
Let time taken to complete the job be x.
Persons 3 4
Days 4 x
Here the number of persons and the number of days are in inverse proportion.
∴ 3/4 = x/4 ⇒ 4Xx=3×4 ⇒ x=3×4/4= 3days
Hence, they will complete the job in 3 days.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
A farmer has enough food to feed 20 animals in his cattle for 6 days. How long would the food last if there were 10 more animals in his cattle?
Let the number of days be x. Total number of animals = 20 + 10 = 30 Animals 20 30 Days 6 x Here, the number of animals and the number of days are in inverse proportion. ∴ 20/30=x/6 ⇒ 30Xx=20x6 ⇒ x=20x6/30 = 4 Hence, the food will last for four days. Class 8 Maths Chapter 11 Exercise 13.2 Solution inRead more
Let the number of days be x. Total number of animals = 20 + 10 = 30
Animals 20 30
Days 6 x
Here, the number of animals and the number of days are in inverse proportion.
∴ 20/30=x/6 ⇒ 30Xx=20×6 ⇒ x=20×6/30 = 4
Hence, the food will last for four days.
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
If a box of sweets is divided among 24 children, they will get 5 sweets each. How many would each get, if the number of the children is reduced by 4?
∵ Each child gets = 5 sweets ∵ 24 children will get 24 x 5 = 120 sweets Total number of sweets = 120 If the number of children is reduced by 4, then children left = 24 – 4 = 20 Now each child will get sweets = 120/20 = 6 sweets Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video for more answerRead more
∵ Each child gets = 5 sweets ∵ 24 children will get 24 x 5 = 120 sweets
Total number of sweets = 120
If the number of children is reduced by 4, then children left = 24 – 4 = 20
Now each child will get sweets = 120/20 = 6 sweets
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
Rehman is making a wheel using spokes. He wants to fix equal spokes in such a way that the angles between any pair of consecutive spokes are equal. Help him by completing the following table: (i) Are the number of spokes and the angles formed between the pairs of consecutive spokes in inverse proportion? (ii) Calculate the angle between a pair of consecutive spokes on a wheel with 15 spokes. (iii) How many spokes would be needed, if the angle between a pair of consecutive spokes is 40°?
Here the number of spokes are increasing and the angle between a pair of consecutive spokes is decreasing. So, it is a inverse proportion and angle at the centre of a circle is 360°. When the number of spokes is 8, then angle between a pair of consecutive spokes = 360°/8 =45° When the number of spokRead more
Here the number of spokes are increasing and the angle between a pair of consecutive
spokes is decreasing. So, it is a inverse proportion and angle at the centre of a circle is 360°.
When the number of spokes is 8,
then angle between a pair of consecutive spokes = 360°/8 =45°
When the number of spokes is 10,
then angle between a pair of consecutive spokes = 360°/10 =36°
When the number of spokes is 12,
then angle between a pair of consecutive spokes = 360°/12 =30°
No. of spokes 4 6 8 10 12
Angle between a pair of consecutive spokes 90° 60° 45° 36° 30°
(i) Yes, the number of spokes and the angles formed between a pair of
consecutive spokes is in inverse proportion.
(ii) When the number of spokes is 15, then angle between a pair of consecutive
spokes = 360°/15 = 24°
(iii) The number of spokes would be needed = 360°/40° = 9°
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/
In a Television game show, the prize money of ₹1,00,000 is to be divided equally amongst the winners. Complete the following table and find whether the prize money given to an individual winner is directly or inversely proportional to the number of winners:
Here number of winners and prize money are in inverse proportion because winners are increasing, prize money is decreasing. When the number of winners are 4, each winner will get = 100000/4 = ₹25,000 When the number of winners are 5, each winner will get = 100000/5= ₹20,000 When the number of winnerRead more
Here number of winners and prize money are in inverse proportion because
winners are increasing, prize money is decreasing.
When the number of winners are 4, each winner will get = 100000/4 = ₹25,000
When the number of winners are 5, each winner will get = 100000/5= ₹20,000
When the number of winners are 8, each winner will get = 100000/8 = ₹12,500
When the number of winners are 10, each winner will get = 100000/10= ₹10,000
When the number of winners are 20, each winner will get = 100000/20 = ₹5,000
Class 8 Maths Chapter 11 Exercise 13.2 Solution in Video
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/