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Re: In the same amount of time a new production assembly robot c
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02 Jan 2020, 08:17
This question is based on Rate and Work.
The formula sued in these problems is Rate * Time = Work done
If two people work together then their rates get added up.
Let rate of old machine be r
Rate of new machine is given as x transmissions/hour (let's denote Transmission/hour as TPH)
Work done by New machine in some time (let's say t) is 8 times the work done by old machine in same time (t)
Using the formula Rate * time = work done
Rate of new machine * t = 8 * Rate of old machine * t
x*t = 8*r*t
=> r = x/8 TPH
Now, when both of them are working together then their rates get added up.
So combined rate = x + r = x + x/8 = 9x/8 TPH
Work done by both together in 5 days= combined rate * 5 * 24 (1 day has 24 hours) = combined rate * 120 = 9*x/8 * 120 = 9x*15 = 135x
So, answer will be D
Hope it helps!