Question 1

How many integers from 1 to 100 exist such that each is divisible by 5 and also has 5 as a digit?

Accepted Answer

5,15,25,35,40,50,55,65,75,85,95 So there are total 11 such type of numbers.

Question 2

The sum of the digits of two-digit number is 14 and the difference between the two digits number is 2. What is the product of the two digits of the two-digit number?

Accepted Answer

Let be the ten's digit be x and unit's digit be y. So the two digit number = 10x + y ( where x > y ) According to question x + y = 14 ....(i) x - y = 2 ....(ii) Solving Eqs. (i) and (ii), we get x = 8 and y = 6 ∴ Required product = 8 x 6 = 48

Question 3

What number should be added to 231228 to make it exactly divisible by 33?

Accepted Answer

Question 4

How many rational numbers are there between 1 and 1000?

Accepted Answer

There can be infinite number of rational numbers between 1 and 1000.

Question 5

The sum of 5 consecutive even numbers A, B, C, D and E is 130. What is the product of A and E?

Accepted Answer

Let 5 consecutive even number be A = x, B = x+2, C = x+4, D = x + 6 and E = x + 8. According to question x + x +2 + x + 4 + x + 6 + x + 8 = 130 ⇒ 5x + 20 = 130 ⇒ x = 22 ∴ A = 22, E = 22 + 8 = 30. ∴ Multiplication of A and E = 22 x 30 = 660

Question 6

The sum of 5 consecutive numbers is equal to 170. what is the product of largest and smallest numbers?

Accepted Answer

Let smallest number = x. Then, x + x + 1 + x + 2 + x + 3 + x + 4 = 170 ⇒ 5x + 10 = 170 ⇒ x = 160 / 5 ⇒ x = 32 ∴ product of smallest and largest number = 32 x 36 = 1152

Question 7

Which of the following number always divides the difference between the square of two consecutive odd numbers?

Accepted Answer

Let the two consecutive odd numbers be 2x+1 and 2x + 3 . ∴ Difference = ( 2x + 3 )2 - ( 2x + 1 )2 = ( 2x + 3 + 2x + 1 )( 2x + 3 - 2x - 1 ) =( 4x + 4 ) x 2 = 8 (x + 1) whis is exactly divisible by 8.

Question 8

9856 x 156 + 9856 x 844 =?

Accepted Answer

9856 x 156 + 9856 x 844 = 9856 x (156 + 844) = 9856 x 1000 = 9856000

Question 9

6674 x 625 =?

Accepted Answer

6674 x 625 = 6674 x (5)4 = 6674 x (104/24 = 66740000/16 = 4171250

Question 10

9998 x 999 =?

Accepted Answer

Exp.= 9998 x 999 = 9998 x (1000-1) = 9998 x 1000 - 9998 x 1 = 9998000 - 9998 = 9988002

Question 11

8888 + 7777 + 666 +? = 19000

Accepted Answer

Let, 8888 +7777 + 666 + x = 19000 Then, 17331 + x = 19000 ∴ x = 19000 - 17331 = 1669

Question 12

4003 -? - 1599 = 716

Accepted Answer

Let, 4003 - x - 1599 = 716 Then, x = 4003 - 1599 - 716 = 4003 - (1599 + 716) = 4003 - 2315 = 1688

Question 13

36000 - 888 = 37000 -?

Accepted Answer

Let 37000 - x = 36000 - 888 Then x = 37000 - 36000 + 888 = 1888

Question 14

What value should come in place of the question mark(?) in the following question? ? +1046 -398 - 69 = 999

Accepted Answer

Let x - 1046 - 398 - 69 = 999 Then x = 999 + 1046 + 398 + 69 = 2512.

Question 15

What value should come in place of the question mark(?) in the following question? ? + 6207 - 9038 = 107

Accepted Answer

Let x + 6207 - 9038 = 107 Then x = (107 +9038) - (6207) = 2938

Question 16

3571 +? - 6086 = 155

Accepted Answer

Let 3571 + x - 6086 = 115 Then, x = 6086 +115 -3571 = 6201-3571 = 2630

Question 17

36800 - 9999 - 3333 - 66 =?

Accepted Answer

36800 - 9999 - 3333 - 66 = 36800 - ( 9999 - 3333 - 66) = 36800 - 13398 = 23402

Question 18

What value should come in place of the question mark(?) in the following question? ? - 4799 = 1714

Accepted Answer

Let x - 4799 = 1714 Then, x = 4799 + 1714 = 6513.

Question 19

What value should come in place of the question mark(?) in the following question? 9501 -? = 3697

Accepted Answer

Let 9501 - x = 3697 Then x = 9501 - 3697 = 5804

Question 20

What value should come in place of the question mark(?) in the following question? 66066 + 6606 + 66 + 6 =?

Accepted Answer

66066 + 6606 + 66 + 6 = 72744

Number System Questions