1 252 can be expressed as a product of primes as ; A) 2x2x3x3x7 B) 2x2x2x3x7 C) 3x3x3x3x7 D) 2x3x3x3x7
3 A number a is said to be perfect if the sum of all its divisors (excluding n itself) is equal to n. An example of perfect number is : A) 6 B) 9 C) 15 D) 21
6 Three numbers which are co-prime to each other are such that the product of the first two is 551 and that of the last two a 1073. The sum of the three numbers is : A) 71 B) 81 C) 85 D) 89
7 The LCM of two numbers is 45 times their HCF. If one of the numbers is 125 and the sum of HCF and LCM is 1150, the other number is : A) 215 B) 220 C) 225 D) 235
8 Product, of two co-prime numbers is 117. Their L.C.M. should be : A) 1 B) 117 C) Equal to their H.C.F D) 235 E) Cannot be calculated
9 The H.C.F. of two numbers is 23 and the other two factors of their L.C.M. are 13 and 14. The larger of the two numbers is : A) 276 B) 299 C) 322 D) 345
10 Three different containers contain 496 litres, 403 litres and 713 litres of mixtures of milk and water respectively. What biggest measure can measure all the different quantities exactly ? A) 1 litres B) 7 litres C) 31 litres D) 41 litres
11 The maximum number of students among them 1001 pens and 910 pencils can be distributed in such a way that each student gets the same number of pens and same number of pencils is : A) 91 B) 910 C) 1001 D) 1911
12 Let N be the greatest number that will divide 1305, 4665 and 6905, leaving the same remainder in each case Then sum of the digits in N is : A) 4 B) 5 C) 6 D) 8
13 Let the least number of six digits, which when divided by 4, 6, 10 and 15 leaves in each case the same remainder of 2, be N. The sum of the digits in N is : A) 3 B) 4 C) 5 D) 6
14 Four different electronic devices make a beep after every 30 minutes, 1 hour, 1.5 hour and 1 hour 45 minutes respectively. All the devices beeped together at 12 noon. They will again beep together at: A) 12 midnight B) 3 a.m. C) 6 a.m D) 9 a.m.
15 252 can be expressed as a product of primes as : A) 2 x 2 x 3 x 3 x 7 B) 2 x 2 x 2 x 3 x 7 C) 3 x 3 x 3 x 3 x 7 D) 2 x 3 x 3 x 3 x 7