Question 1162966
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Let x be the rate of work of older computer.


Then the rate of work of newer computer is 2x, according to the condition.


The combined rate of work of the two computers is x + 2x = 3x.


It means that  3x = {{{1/25}}};  hence,   x = {{{1/75}}} of the job per minute. 


It means the older computer will make the entire job in  75 minutes.


Therefore, the newer computer will do the job in  {{{75/2}}} = 37 minutes and 30 seconds.    <U>ANSWER</U>
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Solved.


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Another (mental) solution is like this . . . 


The newer computer works as fast as two older computers.


Together, the older and the newer computer work as 3 (three) older computers.


Since they do the job in 25 minutes, it is the same as to say that three older computers make the job in 25 minutes.


Hence, one older computer makes the job in 3*25 = 75 minutes.


It implies that the newer computer will complete the job in  75/2 = 37 minutes and 30 seconds.
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Explained with the same answer.