Quantitative Aptitude • Number System & SimplificationMedium
Three bells ring at intervals of 6, 9 and 18 seconds. If they ring together now, after how many seconds will they next ring together?
A. 18 seconds✓ Correct Answer
B. 33 seconds
C. 36 seconds
D. 972 seconds
💡 Solution & Explanation
The bells ring together again after a time that is a multiple of all three intervals, and the first such time is the LCM. LCM of 6 and 9 is 18, and LCM of 18 and 18 is 18. So the bells ring together again after 18 seconds. Adding the intervals or multiplying them gives a common time, but not the first one.
More Quantitative Aptitude Number System & Simplification questions
- A number leaves a remainder of 17 when divided by 48. What remainder will it leave when divided by 6?
- The sum of three consecutive even numbers is 96. What is the largest of them?
- What is the smallest number that must be added to 6,521 so that the result is exactly divisible by 11?
- What is the HCF (highest common factor) of 20 and 25?
- What is the greatest number that divides 504, 193 and 231, leaving remainders 4, 13 and 11 respectively?