Question

Concrete can be purchased by the cubic yard. How much will it cost to pour a slab 13 feet by 13 feet by 3 inches for a patio if the concrete costs $42.00 per cubic yard? Answer only if you know the answer
$197.17

$1774.50

$295.75

$65.72

Answer 1

$65.72

Since the cost is per cubic yard convert the dimensions into yards

• 3 feet = 1 yard ⇔ 13 feet = $\frac{13}{3}$ yards and

• 36 inches = 1 yard ⇒ 3 inches = $\frac{3}{36}$ = $\frac{1}{12}$ yard

volume = $\frac{13}{3}$ × $\frac{13}{3}$ × $\frac{1}{12}$ = $\frac{169}{108}$

cost = $42 × $\frac{169}{108}$ = $65.72

Answer 2

$13(feet) * \frac{1 (yard)}{3 (feet)} * 13 (feet) * \frac{1 (yard)}{3 (feet)} * 3(inches) * \frac{1 (foot)}{12 (inches)} * \frac{1 (yard)}{3 (feet)} = \frac{13*13*3}{3*3*12*3} (yds)^{3}$

= 1.56 cubic yards * $\frac{42.00 (dollars)}{1 (cubic yard)}$ = $65.72

Answer: D