Question

If there are 4 ships at a port and the first one leaves and comes back every three weeks, the second one every nine weeks, the third one every 12 weeks, and the fourth every 24 weeks when will they all be in the port at the same time/when will they be there all at the same week

Answer 1

Answer: After 72 weeks they will be in the port at the same time.

Explanation:

Given, Total ships = 4

The first one leaves and comes back every 3 weeks, the second one every 9 weeks, the third one every 12 weeks, and the fourth every 24 weeks .

So, the number of weeks they will take to be in the port at the same time = L.C.M. (3, 9, 12 , 24) (L.C.M. = least common multiple)

Since, 9= 3 x 3

12 = 2 x2 x 3

24 = 2 x 2x 2 x3

then, L.C.M. (3, 9, 12 , 24)= 2 x 2x 2 x 3 x3 =72

Hence after 72 weeks they will be in the port at the same time.