Question

three night guard A, B and C blow their whistles at intervals of 8, 15 and 18 mins respectively, if they blow at 11.00pm, when next are they expected to blow together

Answer 1

Hey!

Your answer is 5:00 am!

Explanation:

1) Find the LCM of 8, 15, 18...360

2) 360 mins = 6 hours

3) 11:00 pm + 6 hours = 5:00 am

Hope this helps!

Answer 2

5:00 AM

Solution:

we will have to find the lowest common multiple of 8 , 5 and 18.

Since they blow their whistles once every 8/5/18 minutes.. you can imagine it as the multiplication table for these numbers. The number on which all three overlap, is the LCM and hence the amount of time after they will blow their whistles together.

The LCM is 360

therefore, the guards will blow their whistles together 360 minutes after 11:00pm

360 minutes = 6 hours

6 hours after 11: 5:00AM