Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
A mechanic can install carburetors in 3 cars every 4 hours. At that rate, how long will it take the mechanic to install carburetors in 5 cars?
(A) 6 hr 20 min
(B) 6 hr 40 min
(C) 7 hr 15 min
(D) 7 hr 30 min
(E) 7 hr 45 min
The Correct answer is B.
Explanation
From the information given, you can write the proportion cars is to hours as cars is to hours, where represents the number of hours the mechanic will take to install carburetors in cars. This gives , which simplifies to . Therefore, hours. Since hour is minutes, is hours minutes.