Question

1. Suppose you want to buy concrete for a 36ft by 24 ft by 9 in. patio. If concrete costs $55/yd^3, how much will the concrete for the patio cost?

2. A cylinder has a volume of about 500 cm^3 and a height of 10 cm. What is the lenght of the radius to the nearest tenth of a cm?

Answer 1

36 ft = 12 yards
24 ft = 8 yards
9 in = 0.25 yards

12 * 8 * 0.25 * 55 = ?


V=πr^2h
500 = 3.14 * r^2 * 10

Solve for r

Answer 2

500=3.14*R^2*10
500=31.4*R^2

R^2=500/31.4
R^2=15.92
R= √15.92
R=3.99 or 4 cm