Question

Question #c41bf

Answer 1

`60` minutes
See a solution process below:

Explanation:

Assuming each teacher can grade an essay in the same amount of time:

`2" teachers" xx 90 " minutes" = 180" minutes"`

It took the two teachers `180` total minutes to grade `30` essays.

If we divide the `180` minutes by `3` we can find how long it would take for 3 teachers:

`(180" minutes")/3 = 60" minutes"`

It would take 3 teachers `60` minutes to grade the `30` essays.