Question
A and B can complete a piece of work in 12 days, B and C
in 15 days and A and C in 20 days. In how many days can B alone complete the work?Solution
ATQ, Let rates be a, b, c. a + b = 1/12 b + c = 1/15 a + c = 1/20 Add: 2(a + b + c) = 1/12 + 1/15 + 1/20 = (5 + 4 + 3)/60 = 12/60 = 1/5 ⇒ a + b + c = 1/10 b = (a + b + c) − (a + c) = 1/10 − 1/20 = 1/20 So B alone takes 20 days.
- Find the wrong number in the given number series.
15, 23, 35, 51, 71, 85 42, 32, 60, 48, 96, 84
Find the wrong number in the given number series.
20, 33, 50, 69, 93, 121
- Find the wrong number in the given number series.
420, 369, 318, 277, 238, 225 1648, 1690, 1741, 1807, 1938, 2140
21Â Â Â Â Â Â Â Â Â Â 32Â Â Â Â Â Â Â Â Â Â 54Â Â Â Â Â Â Â Â Â Â 86Â Â Â Â Â Â Â Â Â Â 131Â Â Â Â Â Â Â Â 186
...Find the wrong number in the given number series.
1, 8, 27, 65, 125, 216A-5,  A,  35,  52, 78, 115
27, 35, 51, 75, 109, 147
164, 304, 433, 551, 658, 752