Question

James can hammer a 2-inch nail in 4 seconds. His friend Lindon can hammer a 2-inch nail in 5 seconds. If both start hammering nails at the same time, 1:15:40p.m. when will they next start hammering a nail at the same time?

Answer 1

James

1 nail in 4 sec

Lindon

1 nail in 5 seconds

then we can do the next operations, find the minimum common multiple of 4 and 5 that is 20

that is the quantity of seconds

`\begin{gathered} 1\colon15\colon40\text{ + 0:0:20} \\ 1\colon16\colon00 \\ \\ \end{gathered}`

they start hammering a nail at the same time at 1:16:00