Question: A racecar driver has completed 12 1/2 laps of a 50 lap race. What fractional part of the race remains?
a. 1/4 b. 1/5 c. 3/4 d. 4/5 e. 75/2
Answer: The driver has 50 – 12 1/2 or 37 1/2 laps to go out of the . Therefore, (37 1/2)/50 is the fractional part of the race remaining. This is equivalent to 3/4, which is answer C.
a. (1/4) This is the racing part completed by the driver.
b. (1/5) This comes from mistakenly dividing by , the latter number coming from adding both lap amounts. The race is only .
d. (4/5) This comes from taking the fraction in response B and subtracting it from 1.
e. (75/2) This comes from , but that’s how many laps are left – the driver is only in one race, not !