BTGmoderatorDC wrote:A company uses 2 machines to fill an order for 3,360 bottle caps. Machine A can produce 72 bottle caps every 24 minutes, and it can run for 4 hours before it must undergo a 3-hour recalibration procedure. Machine B can produce 48 bottle caps every 12 minutes, and it can run for 4 hours before it must undergo a 2-hour recalibration procedure. If both machines begin working at the same time, and are working whenever they are not being recalibrated, then how many of the 3,360 bottle caps are made by machine B ?

a. 1,440

b. 1,620

c. 1,680

d. 1,920

e. 2,160

OA D

Source: Princeton Review

Given that Machine A can produce 72 bottle caps every 24 minutes, and it can run for 4 hours, it will produce 72/24 * 60 * 4 = 720 caps in 4 hours and that Machine B can produce 48 bottle caps every 12 minutes, and it can run for 4 hours, it will produce 48/12 * 60 * 4 = 960 caps in 4 hours.

Thus, in 4 hours, Machine A and B together will produce 720 + 960 = 1,680 caps. So, they would need 3360/1680 = 2 * 4 = 8 hours to produce 3,360 caps.

Thus, the number of caps out of the 3,360 bottle caps made by machine B = 2*960 = 1920

The correct answer: D

Hope this helps!

-Jay
_________________
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BTGmoderatorDC wrote:A company uses 2 machines to fill an order for 3,360 bottle caps. Machine A can produce 72 bottle caps every 24 minutes, and it can run for 4 hours before it must undergo a 3-hour recalibration procedure. Machine B can produce 48 bottle caps every 12 minutes, and it can run for 4 hours before it must undergo a 2-hour recalibration procedure. If both machines begin working at the same time, and are working whenever they are not being recalibrated, then how many of the 3,360 bottle caps are made by machine B ?

a. 1,440

b. 1,620

c. 1,680

d. 1,920

e. 2,160

OA D

Source: Princeton Review

Given that Machine A can produce 72 bottle caps every 24 minutes, and it can run for 4 hours, it will produce 72/24 * 60 * 4 = 720 caps in 4 hours and that Machine B can produce 48 bottle caps every 12 minutes, and it can run for 4 hours, it will produce 48/12 * 60 * 4 = 960 caps in 4 hours.

Thus, in 4 hours, Machine A and B together will produce 720 + 960 = 1,680 caps. So, they would need 3360/1680 = 2 * 4 = 8 hours to produce 3,360 caps.

Thus, the number of caps out of the 3,360 bottle caps made by machine B = 2*960 = 1920

The correct answer: D

Hope this helps!

-Jay
_________________
Manhattan Review GRE Prep

Locations: Manhattan GMAT | Free LSAT Practice Questions | LSAT Prep Courses Manchester | SAT Prep Courses Hong Kong | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.