Question
Two pipes A and B are opened together to fill a tank.
Both the pipes fill the tank in time “x”. If A separately takes 8 minute more time than “x” to fill the tank and B takes 50 minute more time than “x” to fill the tank, then find the value of x ?Solution
Let x = time (min) to fill tank together A alone: x + 8 B alone: x + 50 Rates: 1/(x+8) + 1/(x+50) = 1/x Solve: [(x+50) + (x+8)] / [(x+8)(x+50)] = 1/x (2x + 58) * x = (x+8)(x+50) 2x2 + 58x = x2 + 58x + 400 x2 = 400 x = 20 (positive time) Answer: 20 minutes
105 107 111 114 ? 127
8 6 2 ? -1 9.5
...64 48 36 22 16 8
(45)2 ÷ ∛729 + (35)2 ÷ 1.4 =?
24, 33, 50, ?, 108, 149
16 4 2 1.5 1 1.875
...Find the wrong number in the given series.
3 1.5 1.5 ? 4.5 11.25
...18 434 642 746 798 ?
...720 ? 240 180 144 120
...If 204 196 223 x 284
Then, what is the average of the numbers of the above series?
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