1156 is a perfect square because its prime factorisation is 2² × 17². All prime factors appear in pairs, so it equals (2 × 17)² = 34². On the other hand, 2800 = 2⁵ × 5² × 7. The factor 2 appears five times and 7 is unpaired, so we cannot group all the factors into pairs. Hence, 2800 is not a perfectRead more
1156 is a perfect square because its prime factorisation is 2² × 17². All prime factors appear in pairs, so it equals (2 × 17)² = 34². On the other hand, 2800 = 2⁵ × 5² × 7. The factor 2 appears five times and 7 is unpaired, so we cannot group all the factors into pairs. Hence, 2800 is not a perfect square, while 1156 is.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
156 is not a perfect square because its prime factors are 2 × 2 × 3 × 13. Although 2 × 2 can form a pair, 3 and 13 remain unpaired. A perfect square must have all its prime factors in pairs. Since we cannot group all the factors of 156 into equal pairs, it cannot be written as a number multiplied byRead more
156 is not a perfect square because its prime factors are 2 × 2 × 3 × 13. Although 2 × 2 can form a pair, 3 and 13 remain unpaired. A perfect square must have all its prime factors in pairs. Since we cannot group all the factors of 156 into equal pairs, it cannot be written as a number multiplied by itself. Therefore, 156 is not a perfect square.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
Khoisnam realized that each locker would be toggled for every factor it has. Most numbers have even factors because they come in pairs. However, perfect squares have one repeated factor, making their count odd. Since an odd number of toggles leaves a locker open, only perfect square locker numbers (Read more
Khoisnam realized that each locker would be toggled for every factor it has. Most numbers have even factors because they come in pairs. However, perfect squares have one repeated factor, making their count odd. Since an odd number of toggles leaves a locker open, only perfect square locker numbers (like 1, 4, 9…) remain open. This insight helped Khoisnam determine which lockers would stay open without watching the whole process.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
We can use the insight about factor pairs to find all numbers with an odd number of factors. Only perfect squares like 1 (1×1), 4 (2×2), 9 (3×3), etc., have a repeated factor, giving them an odd count. These square numbers are the only ones toggled an odd number of times, so only they remain open. TRead more
We can use the insight about factor pairs to find all numbers with an odd number of factors. Only perfect squares like 1 (1×1), 4 (2×2), 9 (3×3), etc., have a repeated factor, giving them an odd count. These square numbers are the only ones toggled an odd number of times, so only they remain open. This understanding helps in identifying perfect squares just by counting their factors.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
Most numbers have an even number of factors, as they come in factor pairs. For example, 6 has 1×6 and 2×3. However, perfect square numbers like 36 have one repeated factor (6×6), making the total number of factors odd. So, only perfect squares have an odd number of factors. This property is key to sRead more
Most numbers have an even number of factors, as they come in factor pairs. For example, 6 has 1×6 and 2×3. However, perfect square numbers like 36 have one repeated factor (6×6), making the total number of factors odd. So, only perfect squares have an odd number of factors. This property is key to solving the locker puzzle and understanding which lockers stay open.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
Find whether 1156 and 2800 are perfect squares using prime factorisation.
1156 is a perfect square because its prime factorisation is 2² × 17². All prime factors appear in pairs, so it equals (2 × 17)² = 34². On the other hand, 2800 = 2⁵ × 5² × 7. The factor 2 appears five times and 7 is unpaired, so we cannot group all the factors into pairs. Hence, 2800 is not a perfectRead more
1156 is a perfect square because its prime factorisation is 2² × 17². All prime factors appear in pairs, so it equals (2 × 17)² = 34². On the other hand, 2800 = 2⁵ × 5² × 7. The factor 2 appears five times and 7 is unpaired, so we cannot group all the factors into pairs. Hence, 2800 is not a perfect square, while 1156 is.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/ganita-prakash-chapter-1/
See lessIs 156 a perfect square?
156 is not a perfect square because its prime factors are 2 × 2 × 3 × 13. Although 2 × 2 can form a pair, 3 and 13 remain unpaired. A perfect square must have all its prime factors in pairs. Since we cannot group all the factors of 156 into equal pairs, it cannot be written as a number multiplied byRead more
156 is not a perfect square because its prime factors are 2 × 2 × 3 × 13. Although 2 × 2 can form a pair, 3 and 13 remain unpaired. A perfect square must have all its prime factors in pairs. Since we cannot group all the factors of 156 into equal pairs, it cannot be written as a number multiplied by itself. Therefore, 156 is not a perfect square.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/ganita-prakash-chapter-1/
See lessBefore the process begins, Khoisnam realises that he already knows which lockers will be open at the end. How did he figure out the answer? [Hint: Find out how many times each locker is toggled.]
Khoisnam realized that each locker would be toggled for every factor it has. Most numbers have even factors because they come in pairs. However, perfect squares have one repeated factor, making their count odd. Since an odd number of toggles leaves a locker open, only perfect square locker numbers (Read more
Khoisnam realized that each locker would be toggled for every factor it has. Most numbers have even factors because they come in pairs. However, perfect squares have one repeated factor, making their count odd. Since an odd number of toggles leaves a locker open, only perfect square locker numbers (like 1, 4, 9…) remain open. This insight helped Khoisnam determine which lockers would stay open without watching the whole process.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/ganita-prakash-chapter-1/
See lessCan you use this insight to find more numbers with an odd number of factors?
We can use the insight about factor pairs to find all numbers with an odd number of factors. Only perfect squares like 1 (1×1), 4 (2×2), 9 (3×3), etc., have a repeated factor, giving them an odd count. These square numbers are the only ones toggled an odd number of times, so only they remain open. TRead more
We can use the insight about factor pairs to find all numbers with an odd number of factors. Only perfect squares like 1 (1×1), 4 (2×2), 9 (3×3), etc., have a repeated factor, giving them an odd count. These square numbers are the only ones toggled an odd number of times, so only they remain open. This understanding helps in identifying perfect squares just by counting their factors.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/ganita-prakash-chapter-1/
See lessDoes every number have an even number of factors?
Most numbers have an even number of factors, as they come in factor pairs. For example, 6 has 1×6 and 2×3. However, perfect square numbers like 36 have one repeated factor (6×6), making the total number of factors odd. So, only perfect squares have an odd number of factors. This property is key to sRead more
Most numbers have an even number of factors, as they come in factor pairs. For example, 6 has 1×6 and 2×3. However, perfect square numbers like 36 have one repeated factor (6×6), making the total number of factors odd. So, only perfect squares have an odd number of factors. This property is key to solving the locker puzzle and understanding which lockers stay open.
For more NCERT Solutions for Class 8 Mathematics Ganita Prakash Chapter 1 A Square and A Cube Extra Questions & Answer:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/ganita-prakash-chapter-1/
See less