Question
Two pipes A and B can fill a tank in 12 min., and 16
min, respectively. If both the pipes are opened simultaneously, after how much time A should be closed so that the tank is full in 12 minutes?Solution
Let A be closed after x minutes. Then, Part filled by (A + B) in x min. + part filled by B in (12 – x) min. = 1 x (1/12 + 1/16 ) + (12 – x ) × 1/16 = 1 ⟹ (7 x)/48 + (12 - x)/16 = 1 ⟹ (7 x)/48 + 3/4 - x/16 = 1 ⟹ (4 x)/48 = 1/4 ∴ x = 3 ∴ Hence, A must be closed after 3 minutes.
4096 2048 514 64 4
...69 119 156 ? 199 209
24 25 46 ? 572 2885
...52 26 39 97.5 ?
...4 14 130 512 �...
4 8 12 48 ? 432
...3, 4, 10, 33, 136, ?, 4116
7 26 63 126 215 342
...The question below is based on the given series I. The series I satisfy a certain pattern, follow the same pattern in series II and answer the questions...
Find the wrong number in the given series.
12, 18, 27, 42, 62, 87
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