Assuming that your driveway is rectangular, just mult. the length and width together to get the area:
(19 ft)(10.5 ft) = 199.5 ft^2
C is the correct answer choice.
Write and solve an equation of ratios, as follows:
15 250
----- = ------- = 10/12.
x 300
Then 15(12) = 10x, and x = 18. The company could well predict that 18 out of the 300 phones it sells in July will be defective, based upon past history.