Perfect Numbers

Q.

Write the greatest and smallest three digit number?

Q.

A number for which sum all its factors is equal to twice number is called ?

Q. A perfect number is a number whose sum of factors is equal to

1. twice the number.
2. thrice the number.
3. the number itself.

Q. A perfect number is a number whose sum of factors is equal to

1. twice the number.
2. thrice the number.
3. the number itself.

Q.

Question 153
On the following numbers, which is the greatest and which is the smallest?
38051425, 30040700, 67205602

Q. Round off 134 to nearest tens place.

1. 120
2. 130
3. 140
4. 150

Q.

In the answer of Question Number 139 it is written -

By definition, a number, for which the sum of all its factors excluding the number itself is equal to twice the number, is called perfect number.

Should it be as below -

a number, for which the sum of all its factors excluding the number itself is equal to the number, is called perfect number.

Q. Find the smallest number among the following: 1346, 1643, 1463, 1364 .

1. 1346
2. 1643
3. 1364
4. 1463

Q.

Which of the following numbers are perfect numbers?

1. whose sum of all its factors is equal to twice the number.

2. 27

3. whose sum of all its factors is equal to thrice the number.

4. none of these

Q. Show that 496 is a perfect number.

Q. A perfect number is a number whose sum of factors is equal to

1. twice the number.
2. thrice the number.
3. the number itself.

Q.

Which of the following numbers exceeds 9999999 by 1?

1. 10000000

2. 1000000

3. 10000

4. 9999998

Q. A perfect number is a number whose sum of factors is equal to

1. thrice the number.
2. the number itself.
3. twice the number.

Q. Find the greatest number among the following: 2345, 2534, 2453, 2543.

1. 2345
2. 2534
3. 2453
4. 2543

Q. 7 centimetres = ___ millimetres.

1. 0.07
2. 7
3. 70
4. 0.7

Q.

How it became 88=2x2x2x11=2(3)x11(1)(3+1)(1+1)=4x2=8

Q.

27596381 is _______ 7965412.

1. less than or equal to

2. greater than

3. equal to

4. less than

Q. A perfect number is a number whose sum of factors is equal to

1. twice the number.
2. thrice the number.
3. the number itself.

Q. Show that $496$ is a perfect number.

Q. A perfect number is a number whose sum of factors is equal to

1. twice the number.
2. thrice the number.
3. the number itself.

Q.

Aashu's elder sister asked him to make the smallest number using the digits of 8734. What is the number? Also, find the sum of these numbers. [3 MARKS]

Q.

A perfect number is:

1. a number which is co-prime to every other number.

2. a number whose sum of factors is equal to thrice the number.

3. a number whose sum of factors is equal to twice the number.

4. a number whose sum of its digits is equal to the product of its digits.

Q.

A perfect number is:

1. whose sum of all its factors is equal to twice the number.

2. 27

3. whose sum of all its factors is equal to thrice the number.

4. none of these

Q.

Find the difference $:$

$9000134-7777777$

Q. Round off 457 to nearest hundreds place.

1. 600
2. 400
3. 300
4. 500

Q. A perfect number is a number whose sum of factors is equal to

1. thrice the number.
2. twice the number.
3. the number itself.

Q. Raju covers 3 km of distance each day. How many centimetres does Raju cover each day?

1. 300000 cm
2. 300 cm
3. 30 cm
4. 3000 cm

Q.

using pattern, find : $1256\times 99$

Q. Find the greatest number among the following: 2345, 2534, 2453, 2543.

1. 2345
2. 2453
3. 2534
4. 2543

Q.

A perfect number is:

1. whose sum of all its factors is equal to twice the number.

2. none of these

3. 27

4. whose sum of all its factors is equal to thrice the number.