7 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
8 The H.C.F. of two numbers is 11 and their L.C.M. is 7700. If one or the numbers is 275, then the other is : A) 279 B) 283 C) 308 D) 318
9 The product of the L.C.M. and H.C.F of two numbers is 24. The difference of two numbers is 2. Find the numhers A) 2 and 4 B) 6 and 4 C) 8 and 6 D) 8 and 10
10 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
11 The least number of five digits which is exactly divisible by 12, 15 and 18, is : A) 10010 B) 10015 C) 10020 D) 10080
12 The least number which is a perfect square and is divisible by each of the numbers 10, 20 and 24, is A) 1600 B) 3600 C) 6400 D) 14400
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 Find the least number which when divided by 16, 18, 20 and 25 leaves 4 as remainder in each case, but when divided by 7 leaves no remainder. A) 17004 B) 18000 C) 18002 D) 18004
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