Timer
00:00
Answers
A
B
C
D
E
Stats
Difficulty—
Larry can build a model car in 3 hours, Moe can build the same car in 4 hours, and Fred can build the car in 5 hours. If the two fastest boys work together, how much of the car can they build in one hour?
A. 1/12
B. 2/7
C. 7/12
D. 8/15
E. 9/20
The OA is C.
We can say the car has 60 parts (lcm of 3, 4 and 5) in all...
L can do 60 parts in 3 hours means 20 parts/hour
Similarly, M can do 15 parts/hour
And F can do 12 parts/hour.
So the L + M (the fastest boys working together) can do 20 + 15 = 35 parts/hour
So, 35/60 = 7/12 in an hour. Option C.
Has anyone another strategic approach to solve this PS question? Regards!
A. 1/12
B. 2/7
C. 7/12
D. 8/15
E. 9/20
The OA is C.
We can say the car has 60 parts (lcm of 3, 4 and 5) in all...
L can do 60 parts in 3 hours means 20 parts/hour
Similarly, M can do 15 parts/hour
And F can do 12 parts/hour.
So the L + M (the fastest boys working together) can do 20 + 15 = 35 parts/hour
So, 35/60 = 7/12 in an hour. Option C.
Has anyone another strategic approach to solve this PS question? Regards!
