5 builders took 6 hours to dig a trench.How long would it have taken 3 builders to dig an identical trench?​

We can use the formula:

(time 1 * workers1) = (time2 * workers2)

where time1 and workers1 are the initial values, time2 is what we're trying to find, and workers2 is the new number of workers.

Plugging in the values we have:

(6 hours * 5 workers) = (time2 * 3 workers)

Solving for time2:

time2 = (6 hours * 5 workers) / (3 workers)

time2 = 10 hours

Therefore, it would take 3 builders 10 hours to dig an identical trench.