Question

Mr. Brackett works in factory with his two sons. He is really happy with his job because he gets to spend some time with his beloved sons not only at home but also at work! He is allowed to take a break every 140 minutes while his two sons are allowed to take breaks in 210 minutes and 280 minutes. How many minutes will they have to wait after their first break together to get together again?

Answer 1

840 minutes

Explanation:

We solve this question using the LCM Method

Find and list multiples of each number of minutes which is given in the quest as 140, 210 and 280 minutes until the first common multiple is found. This is the lowest common multiple.

Multiples of 140:

140, 280, 420, 560, 700, 840, 980, 1120

Multiples of 210:

210, 420, 630, 840, 1050, 1260

Multiples of 280:

280, 560, 840, 1120, 1400

Therefore,

LCM(140, 210, 280) = 840

Therefore, they would have to wait after their first break together to get together again after 840 minutes