Need help on letter d.

2men and 7 boys can do a piece of working 4 days.it is done by 4 men and 4 boys in 3 days how long would it take for 1man or one boy to do it alone

You eat 8 strawberries and your friend eats 12 strawberries from a bowl. there are 20 strawberries left. which equation and solution give the original number of strawberries?

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?