LCM and HCF MCQs

Question 1

Three friends started running together on a circular track at 8:00:00 am. Time taken by them to complete one round of the track is 15 min, 20 min, 30 min respectively. If they run continuously without any halts, then at what time will they meet again at the starting point for the fourth time ?

• 8:30:00 am
• 9:00:00 pm
• 12:00:00 pm
• 12:00:00 am

Question 2

The LCM of two co-prime numbers is 117. What is the sum of squares of the numbers ?

• 220
• 1530
• 250
• 22

Question 3

Two numbers are in the ratio 3 : 5. If their L.C.M. is 75. what is sum of the numbers?

• 25
• 45
• 40
• 50

Question 4

Ratio of two numbers is 3:2. If LCM of numbers is 60, then smaller number is?

• 20
• 30
• 40
• 50

Question 5

Three numbers are in the ratio of 2 : 3 : 4 and their L.C.M. is 240. Their H.C.F. is:

• 40
• 20
• 30
• 10

Question 6

What is the lowest common multiple of 12, 36 and 20?

• 120
• 180
• 360
• 240

Question 7

What is the least number which when divided by 4, 5, 6 and 7 leaves a remainder 3, but when divided by 9 leaves no remainder?

• 1683

• 1263

• 843

• 423

Question 8

The LCM. of two numbers is 30 and their HCF. is 15. If one of the numbers is 30, then what is the other number?

• 30
• 25
• 15
• 20

Question 9

What is the least number which is exactly divisible by 6, 7, 9 and 11 ?

• 1386
• 1246
• 1122
• 1432

Question 10

What is the least number which is exactly divisible by 6, 12, 9 and 18?

• 96
• 36
• 24
• 81