If the students of 9th class are arranged in a row of 6, 8, 12 or 16, no student is left behind. Then the possible number of students in the class is

• 60

• 72

• 80

• 80

In a division sum, the divisor is 4 times the quotient and twice the remainder. If a and b are respectively the divisor and the dividend, then

H.C.F. of  is

There are five bells which start ringing together at intervals of 3, 6, 9, 12 and 15 seconds respectively. In 36 minutes, how many times will the bells ring simultaneously?

• 13

• 12

• 6

• 6

The greatest number among  is

Two numbers are in the ratio 5 : 6. If their H.C.F. is 4, then their L.C.M. will be

• 90

• 96

• 120

• 120

17.

The greatest number, that divides 43, 91 and 183 so as to leave the same remainder in each case is

• 9

• 8

• 4

• 4

The H.C.F. and L.C.M. of two numbers are 21 and 84 respectively. If the ratio of the two numbers is 1 : 4, then the larger of the two numbers is

• 12

• 108

• 48

• 48

Let x be the smallest number, which when added to 2000 makes the resulting number divisible by 12, 16, 18 and 21. The sum of the digits of x is

• 7

• 5

• 6

• 4

The greatest number among 
3⁵⁰, 4⁴⁰, 5³⁰ and 6²⁰ is

• 3⁵⁰

• 4⁴⁰

• 5³⁰

• 5³⁰