This question is based on Rate and Work. There are three theories involved

1. Rate * Time = Work Done

2. If two people are working together then their rates get added up.

3. If n number of machines with same rate(let sat R) are working together then their rates get added up and combined rate is nR.

Coming to the question:

Let rate of each computer be R. So rate of 4 computer will be 4R.

Using Rate * Time = Work Done

4R * 4mins = 4 letters

=> R = 1/4 Letters/min

Rate of 100 computers will be 100R = 100* 1/4 letters/min = 25 letters/min

Using Rate * Time = Work done

25 letters/min * Time = 100 letters

=> Time = 100/25 min = 4 mins.

So, Answer will be A

Hope it helps!

Carcass wrote:

A certain form letter is to be sent to prospective customers. If 4 model-X computers working independently can do a combined total of 4 of the letters in 4 minutes, then 100 model-X computers working independently can do a combined total of 100 of the letters in exactly how many minutes?

(A) 4 min

(B) 10 min

(C) 25 min

(D) 40 min

(E) 100 min

Kudos for the right answer and explanation

_________________

Ankit

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