Question
P alone can finish a piece of work ‘M’ in 6 days
while Q takes 3 days to finish it alone. P, Q and R working together can finish the work ‘N’ which is 10 times of work ‘M’ in 4 days. How long will R take to finish work ‘N’, when working alone?Solution
 Let the work ‘M’ = 6 units (LCM of 6 and 3) Efficiency of P = 6/6 = 1 units Efficiency of Q = 6/3 = 2 units Efficiency of P, Q and R = (6 × 10)/4 = 15 units per day Efficiency of R = 15 – (1 + 2) = 12 units per day Time taken by R to finish work ‘N’ = 60/12 = 5 days
12Â Â Â Â Â Â Â Â Â Â Â Â Â 10Â Â Â Â Â Â Â Â Â Â Â Â 13Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 18.5Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 25.50Â Â Â Â Â Â Â ...
7, 14, 42, 210, 1470, ?
6, 17, 21, 47, ?, 107
21     84      168      172     ?     348
...315 146 267 ? 235 210
14 20 35 ? 433 2167
...18, 32, 50, 82, 132, ?
840 400 180 ? 15 -12.5
...22Â Â Â 23Â Â Â Â 32Â Â Â Â 57Â Â Â 106Â Â Â ?
Three series are given below. You have to find the values of P, Q and R, then establish a relationship among them.
I:Â Â Â 210, P , 233, 64,...
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