Problem Solving

BTGModeratorVI wrote: ↑

Tue Feb 16, 2021 8:16 am

The amounts of time that three secretaries worked on a special project are in the ratio of 1 to 2 to 5. If they worked a combined total of 112 hours, how many hours did the secretary who worked the longest spend on the project?

A) 80
B) 70
C) 56
D) 16
E) 14

Answer: B
Source: official guide

The amounts of time that three secretaries worked on a special project are in the ratio of 1 to 2 to 5
1 + 2 + 5 = 8
So the above information is telling us that, for every 8 hours worked, the first secretary worked 1 hour, the second secretary worked 2 hours, and the third secretary worked 5 hours.
In other words, of the 3 secretaries contributed to 1/8, 2/8 and 5/8 of the job.

If they worked a combined total of 112 hours, how many hours did the secretary who worked the longest spend on the project?
The secretary who worked the longest is the one who contributed 5/8 of the job.
Since the job took a total of 112 hours, the number of hours that secretary worked = 5/8 of 112
= 5/8 x 112
= 70 hours

Answer: B