HCF and LCM Quiz Set 002 | Maths Aptitude Quiz Questions and Mock Test on HCF and LCM Set 2 | mock tests for Bank PO, SSB/SSC Exams, SO Clerical Exam, GATE Exam, LIC AO, GIC AO, etc.

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Question 1

Three lights are flashing at regular intervals. They, respectively, flash after 18, 36 and 54 seconds. How many times do they together flash in 1836 seconds?

18 times.

19 times.

17 times.

20 times.

Soln.
Ans: a

They will together flash after the LCM of their times. The LCM of 18, 36 and 54 = 108. So they will flash 1 + $1836/108$ = 18 times.

Solution | Discuss! | Chapters»

Question 2

Which is the least number which must be added to 4196 so that it becomes divisible by 24, 50 and 105?

Soln.
Ans: a

The LCM of 24, 50 and 105 = 4200. The lcm when divided by either of these numbers leaves the remainder 0. The minimum number to be added is 4200 - 4196 = 4.

Solution | Discuss! | Chapters»

Question 3

What is the LCM of ${6/13}$, $3{3/5}$ and ${2/9}$?

18.

19.

20.

21.

Soln.
Ans: a

The LCM of numerators 6, 18 and 2 is 18. The HCF of denominators 13, 5 and 9 is 1. So the required LCM of the given fractions is 18/1 = 18.

Solution | Discuss! | Chapters»

Question 4

Which is the smallest number which when divided by 15, 9 or 16 leaves 9, 3, 10 as the respective remainders?

714.

715.

713.

716.

Soln.
Ans: a

By inspection, the difference between the numbers and their respective remainders is same = 6. The LCM of 15, 9 and 16 = 720. So the required number is 720 - 6 = 714.

Solution | Discuss! | Chapters»