What is the answer to this question?

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

(05.02)a farmer has decided to divide his land area in half in order to plant soy and corn. calculate the area of the entire area so he knows how much soil is needed. a parallelogram with a height of 6 yards and side length 9 yards. the height forms a triangle with the slanted side of the rhombus with a base of 2.5 yards. rhombus is split into a soy half and a corn half. each bag of soil covers 40 square yards. how many bags should the farmer purchase?

If a and −a are numbers on the number line, which expression must give the distance between them? a) 0 b) a c) |2a| d) |a|