Question
A and B together can do a piece of work in 15 days which
B and C together can do in 20 days. After A has been working at it for 3 days and then by B for 11 days & then C finishes it in 20 days. In how many days B could finish the work?Solution
A + B = 15 days B + C = 20 days Work = L.C.M (15, 20) = 60 A + B = 4 B + C = 3 (A + B) × 3 + (B + C) × 8 + 12C = 60 4 × 3 + 3 × 8 + 12C = 60 12 + 24 + 12C = 60 12C = 60 – 36 12 C = 24 C = 2 Now, B + C = 3 B + 2 = 3 B = 1 ∴ B takes = 60/1 = 60 days
186, 179, 170, 162, 146, 131, 114
11Â Â Â Â Â Â Â Â Â Â 9Â Â Â Â Â Â Â Â Â Â Â Â Â 20Â Â Â Â Â Â Â Â Â Â 18Â Â Â Â Â Â Â Â Â Â 37Â Â Â Â Â Â Â Â Â Â 36
...128, 128, 64, 192, 42 , 240
Find the wrong number in the given series.
46, 104, 184, 404, 760, 1586
100, 75, 59, 55, 46, 45
9Â Â Â Â 20Â Â Â Â Â 63Â Â Â Â Â Â 255Â Â Â Â Â Â 1285Â Â Â Â Â 7716
...20000, 500, 25, 2.5, 0.5, 0.4,  0.16
384, 1152, 144, 432, 56, 162
Find the wrong number in the given number series.
7, 15, 46, 93, 282, 561
Find the wrong number in the given number series.
976, 720, 495, 297, 130, - 14Â
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