Q.

A software company sets up m number of computer systems to finish an assignment in 17 days. If 4 computer systems crashed on the start of the second day, 4 more computer systems crashed on the start of the third day and so on, then it took 8 more days to finish the assignment. The value of m is equal to:                 [2024]

1 160  
2 180  
3 150  
4 125  

Ans.

(3)

Let the work done by each computer =k

   Total work =17 mk

Work done on 1 day by m computers =mk

Work done on day 2 by m-4computers =(m-4)k

Work done on day 3 by m-8 computers =(m-8)k

Work done on day 25 =(m-(24×4))k

                                       =(m-96)k

     mk+(m-4)k++(m-96)k=17mk

25m-(4+8++96)=17m

8m=242(4+96)m=150