Bissoy.com
Doctors Medicines MCQs Q&A

Five clocks ring at an interval of 3, 4, 5, 6 and 7 seconds respectively. After how much time they will ring together once they ring together at same time?

Five clocks ring at an interval of 3, 4, 5, 6 and 7 seconds respectively. After how much time they will ring together once they ring together at same time? Correct Answer 7 minutes

The next they ring together will be after LCM of (3, 4, 5, 6, and 7)

⇒ 3 = 1 × 3

⇒ 4 = 2 × 2

⇒ 5 = 1 × 5

⇒ 6 = 2 × 3

⇒ 7 = 1 × 7

∴ LCM of 3, 4, 5, 6 and 7 = 2 × 2 × 3 × 5 × 7 = 420

∴ The clocks ring together at an interval of 420 seconds = 7 minutes

Related Questions

Which of the two conclusions can be drawn based on the given statements? Statement: All clocks are wall clocks. All wall clocks are frames Conclusion : 1. Some clocks are not frames. 2. Some frames are clocks.
Five clocks ring simultaneously at 5 pm. They ring at regular intervals of 12 min, 15 min, 20 min, 30 min, and 60 min respectively. The time when all five clocks ring together next is:
Three statements are followed by three conclusions numbered I, Il and Ill. Assuming the statements to be true even if they do not conform to real-world knowledge, decide which of the conclusions logically follows/follow from the statements. Statements: 1. All watches are clocks. 2. Some clocks are machines. 3. Some machines are gadgets. Conclusions: I. Some watches are machines. Il. Some machines are clocks. Ill. Some gadgets being clocks is a possibility.
4 alarm clocks ring together at 5 am. They ring after 7, 8, 11 and 12 seconds respectively. How many times will they ring together again in the next 3 hours?
Five bells ring together and If the bells ring at intervals 5, 15, 20, 25, 30 seconds respectively, after what interval of time will they ring together again.
Four bells ring at intervals of 5, 10, 12 and 15 minutes respectively. If they start ringing together at 3 o'clock, after what interval of time will they ring together and how many times will they ring together in 18 hours?
Five bells begin to toll together at intervals of 9 seconds, 6 seconds, 4 seconds, 10 seconds and 8 seconds respectively. Starting together, how many times will the bells toll together in a span of 1 hour?
Mean Value theorem is applicable to the and continuous in open interval (a, b) b) Functions continuous in closed interval only and having same value at point ‘a’ and ‘b’ c) Functions continuous in closed interval and differentiable in open interval (a, b) d) Functions differentiable in open interval (a, b) only and having same value at point ‘a’ and ‘b’
Two bells ring at intervals of 63 seconds and 74 seconds. If they both ring at 10 O'clock in the morning together, after how many seconds will they ring together again?
Two bells ring at intervals of 51 seconds and 62 seconds. If they both ring at 10 O'clock in the morning together, after how many seconds will they ring together again?