good question, solving under 2 mins is surely a task for this question where in so much info is given...

from the given details we can say that rate of machine A per hour is 180 and B 240

so lets say that both machines start off at same time:

so 1 to 4 hours : work of A + B = (180+240) * 4= 1680 caps

now from 5th,6th & 7th hrs machine A is off for calibration and 5th & 6th hr machine in 7th hr machine B starts off again and makes 240 caps more

total now is 1680+240 = 1920

starting 8th hour both A & B start working together but condition that B would work till 10th hour only..

8th hour A & B = 180+ 240 = 420 + 1920 = 2340

9th hour A & B= 420 + 2340 = 2760

10th hour A & B = 420 + 2760 = 3180

11th hour only A works = 180 + 3180 = 3360

so machine B has made :

240 * 8 hrs of total work = 1920 caps

IMO D

AkshdeepS 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

_________________

If you liked my solution then please give Kudos. Kudos encourage active discussions.