model 2 find lcm of numbers Section-Wise Topic Notes With Detailed Explanation And Example Questions

Question : 1

What is the least number which when divided by the numbers 3, 5, 6, 8, 10 and 12 leaves in each case a remainder 2 but when divided by 13 leaves no remainder ?

a) 1586

b) 1562

c) 962

d) 312

Question : 2

The smallest perfect square divisible by each of 6, 12 and 18 is

a) 36

b) 108

c) 144

d) 196

Question : 3

The least perfect square, which is divisible by each of 21, 36 and 66 is

a) 231444

b) 213444

c) 214434

d) 214344

Question : 4

Four bells ring at intervals of 4, 6, 8 and 14 seconds. They start ringing simultaneously at 12.00 O’clock. At what time will they again ring simultaneously ?

a) 12 hrs. 3 min. 44 sec.

b) 12 hrs. 3 min. 20 sec.

c) 12 hrs. 3 min.

d) 12 hrs. 2 min. 48 sec.

Question : 5

The LCM of two prime numbers x and y, (x > y) is 161. The value of (3y – x) :

a) 2

b) 1

c) –1

d) –2

Question : 6

Five bells begin to toll together and toll respectively at intervals of 6, 7, 8, 9 and 12 seconds. After how many seconds will they toll together again ?

a) 318 Sec.

b) 504 Sec.

c) 612 Sec.

d) 72 Sec.