Question

A 4 pound roast must be cooked for 30 minutes per pound and must rest for 15 minutes. When must it be put into the oven in order to be ready to be served at 6:00 pm?

Answer 1

it should be 3:45 if im correct

Answer 2

For 1 pound, it needs = 30 min. cooking
so, for 4 pound, it is = 30 * 4 = 120 min. cooking.

Now, 15 min. for rest, so total time needed = 120 + 15 = 135 min.

If you need it at 6:00 PM, then you should put it into the oven at 6:00 PM - 135 min. = 4 PM - 15 min = 3:45

In short, Your Answer would be 3:45 PM

Hope this helps!