If 4 examiners can examine a certain number of answer books in 8 days by working 5 hours a day, for how many hours a day would 2 examiners have to work in order to examine twice the number of answer books in 20 days.

Less examiners, more hours per day (Indirect) More days, less hours per day (Indirect) More answer books, more hours per day (Direct)

Examiners 2:4 Days 20:8 --------- :: 5:x Answer books 1:2

=> x = 4*8*2*5/2*20*1 = 8 hours per day

1

ans 1:4:8:5 = 160 2:2:20:? =320 ? =4 hours

4 examiners, 8 days, 5 hrs= 40 hrs. Let no. of ans books evaluated be 10 each. 2 examiners, 20 days 40 books to be evaluated. since 20 hrs and 20 days its 1 hr per day

answer 20 hours in 8 days by 2 examiners

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