zisis wrote:
Machine A and machine B are each used to manufacture 660 sprockets. It takes machine A 10 hours longer to produce 660 sprockets than machine B. Machine B produces 10 percent more sprockets per hour than machine A. How many sprockets per hour does machine A produces?
A. 6
B. 6.6
C. 60
D. 100
E. 110
We are given that machine A and machine B are each used to manufacture 660 sprockets; thus the work of each machine is 660. We also are given that it takes machine A 10 hours longer to produce 660 sprockets than it takes machine B, and that machine B produces 10% more sprockets per hour than machine A. If we let the rate of machine A = r, then the rate of machine B = 1.1r.
Since time = work/rate:
The time of machine A = 660/r and the time of machine B = 660/(1.1r) = 600/r
Since machine A takes 10 hours longer to produce 660 sprockets than does machine B, we can create the following equation and determine r:
660/r = 600/r + 10
60/r = 10
60 = 10r
6 = r
Thus, machine A produces 6 sprockets per hour.
Answer: A
_________________
5-star rated online GMAT quant
self study course
See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews
If you find one of my posts helpful, please take a moment to click on the "Kudos" button.