Starting position of mine shaft is 10 m above the ground but it moves in opposite direction so it travels the distance (–350) m below the ground. So total distance covered by mine shaft = 10 m – (–350) m = 10 + 350 = 360 m Now, time taken to cover a distance of 6 m by it = 1 minute So, time taken toRead more
Starting position of mine shaft is 10 m above the ground but it moves in opposite
direction so it travels the distance (–350) m below the ground.
So total distance covered by mine shaft = 10 m – (–350) m = 10 + 350 = 360 m
Now, time taken to cover a distance of 6 m by it = 1 minute
So, time taken to cover a distance of 1 m by it = 1/6 minute
Therefore, time taken to cover a distance of 360 m = 1/6×360
= 60 minutes = 1 hour
(Since 60 minutes = 1 hour)
Thus, in one hour the mine shaft reaches –350 below the ground.
(i) Marks given for one correct answer = 3 Marks given for 12 correct answers = 3 x 12 = 36 Radhika scored 20 marks. Therefore, Marks obtained for incorrect answers = 20 – 36 = –16 Now, marks given for one incorrect answer = –2 Therefore, number of incorrect answers = (-16) ÷(-2) = 8 Thus, Radhika hRead more
(i) Marks given for one correct answer = 3
Marks given for 12 correct answers = 3 x 12 = 36
Radhika scored 20 marks.
Therefore, Marks obtained for incorrect answers = 20 – 36 = –16
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-16) ÷(-2) = 8
Thus, Radhika has attempted 8 incorrect questions.
(ii) Marks given for seven correct answers = 3 x 7 = 21
Mohini scores = –5
Marks obtained for incorrect answers = = –5 – 21 = –26
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-26) ÷ (-2) = 13
Thus, Mohini has attempted 13 incorrect questions.
Given: a ÷(b+c) ≠ (a÷b) + (a÷c) a=12, b = -4, c=2 Putting the given values in L.H.S. = 12÷(-4+2) = 12÷(-2) = 12÷(-1/2) = -12/2 =-6 Putting the given values in R.H.S. = [12÷(-4)]+(12÷2) = (12x-1/4)+6=-3+6=3 Since, L.H.S. ≠ R.H.S. Hence verified. Exercise 1.4 Question 2, 3, 4, 5 for more answers vistRead more
Given: a ÷(b+c) ≠ (a÷b) + (a÷c)
a=12, b = -4, c=2
Putting the given values in L.H.S. = 12÷(-4+2)
= 12÷(-2) = 12÷(-1/2) = -12/2 =-6
Putting the given values in R.H.S. = [12÷(-4)]+(12÷2)
= (12x-1/4)+6=-3+6=3
Since, L.H.S. ≠ R.H.S.
Hence verified.
An elevator descends into a mine shaft at the rate of 6 m/min. If the descent starts from 10 above the ground level, how long will it take to reach -350 m?
Starting position of mine shaft is 10 m above the ground but it moves in opposite direction so it travels the distance (–350) m below the ground. So total distance covered by mine shaft = 10 m – (–350) m = 10 + 350 = 360 m Now, time taken to cover a distance of 6 m by it = 1 minute So, time taken toRead more
Starting position of mine shaft is 10 m above the ground but it moves in opposite
direction so it travels the distance (–350) m below the ground.
So total distance covered by mine shaft = 10 m – (–350) m = 10 + 350 = 360 m
Now, time taken to cover a distance of 6 m by it = 1 minute
So, time taken to cover a distance of 1 m by it = 1/6 minute
Therefore, time taken to cover a distance of 360 m = 1/6×360
= 60 minutes = 1 hour
(Since 60 minutes = 1 hour)
Thus, in one hour the mine shaft reaches –350 below the ground.
Exercise 1.4 Question 6, 7
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/
In a class test (+3) marks are given for every correct answer and (-2) marks are given for every incorrect answer and no marks for not attempting any question. (i) Radhika scored 20 marks. If she has got 12 correct answers, how many questions has she attempted incorrectly? (ii) Mohini scores (-5) marks in this test, though she has got 7 correct answers. How many questions has she attempted incorrectly?
(i) Marks given for one correct answer = 3 Marks given for 12 correct answers = 3 x 12 = 36 Radhika scored 20 marks. Therefore, Marks obtained for incorrect answers = 20 – 36 = –16 Now, marks given for one incorrect answer = –2 Therefore, number of incorrect answers = (-16) ÷(-2) = 8 Thus, Radhika hRead more
(i) Marks given for one correct answer = 3
Marks given for 12 correct answers = 3 x 12 = 36
Radhika scored 20 marks.
Therefore, Marks obtained for incorrect answers = 20 – 36 = –16
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-16) ÷(-2) = 8
Thus, Radhika has attempted 8 incorrect questions.
(ii) Marks given for seven correct answers = 3 x 7 = 21
Mohini scores = –5
Marks obtained for incorrect answers = = –5 – 21 = –26
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-26) ÷ (-2) = 13
Thus, Mohini has attempted 13 incorrect questions.
Exercise 1.4 Question 6, 7
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/
Write five pairs of integers (a,b) such that a÷b= -3.One such pair is (6,-2) because 6 ÷(-2) = (-3).
(i) (-6)÷2 = -3 (ii) 9÷(-3) = -3 (iii) 12÷(-4) = -3 (iv) (-9)÷3 = -3 (v) (-15)÷5=-3 Exercise 1.4 Question 2, 3, 4, 5 for more answers vist to: https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/
(i) (-6)÷2 = -3
(ii) 9÷(-3) = -3
(iii) 12÷(-4) = -3
(iv) (-9)÷3 = -3
(v) (-15)÷5=-3
Exercise 1.4 Question 2, 3, 4, 5
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/
Fill in the blanks: 369 ÷ ………….. = 369
369 ÷ 1 = 369 Exercise 1.4 Question 2, 3, 4, 5 for more answers vist to: https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/
369 ÷ 1 = 369
Exercise 1.4 Question 2, 3, 4, 5
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/
Verify that a ÷(b+c) ≠ (a÷b) + (a÷c) for each of the following values of and ,ab . c (a) a=12, b = -4, c=2
Given: a ÷(b+c) ≠ (a÷b) + (a÷c) a=12, b = -4, c=2 Putting the given values in L.H.S. = 12÷(-4+2) = 12÷(-2) = 12÷(-1/2) = -12/2 =-6 Putting the given values in R.H.S. = [12÷(-4)]+(12÷2) = (12x-1/4)+6=-3+6=3 Since, L.H.S. ≠ R.H.S. Hence verified. Exercise 1.4 Question 2, 3, 4, 5 for more answers vistRead more
Given: a ÷(b+c) ≠ (a÷b) + (a÷c)
a=12, b = -4, c=2
Putting the given values in L.H.S. = 12÷(-4+2)
= 12÷(-2) = 12÷(-1/2) = -12/2 =-6
Putting the given values in R.H.S. = [12÷(-4)]+(12÷2)
= (12x-1/4)+6=-3+6=3
Since, L.H.S. ≠ R.H.S.
Hence verified.
Exercise 1.4 Question 2, 3, 4, 5
for more answers vist to:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-1/