Question
The speed of a boat in still water is 15 km/h and the
speed of the stream is 3 km/h. It goes from point A to point B downstream and returns upstream, taking a total time of 6 hours. What is the distance between A and B?Solution
ATQ, Downstream speed = 15 + 3 = 18 km/h Upstream speed = 15 − 3 = 12 km/h Let distance one way = d km Time downstream = d / 18 Time upstream = d / 12 Total time = 6 hours So, d/18 + d/12 = 6 LCM of 18 and 12 = 36 (2d + 3d) / 36 = 6 5d / 36 = 6 5d = 216 d = 216 / 5 = 43.2 km
Find the wrong number in the given number series.
121, 132, 145, 160, 181, 204
Find the wrong number in the given series.
46, 104, 184, 404, 760, 1586
10 3 7 6 40 310
...25Â Â Â 26Â Â Â Â 28Â Â Â Â 32Â Â Â Â 42Â Â Â Â 56
17, 33, 69, 133, 233, 370
- Find the wrong number in the given number series.
4, 10, 22, 46, 92, 186 Find the wrong number in the given number series.
10, 17, 26, 39, 59, 85
24, 41, 58, 75, 94, 109
A-5,  A,  35,  52, 78, 115
3, 4, 9, 28, 116, 566, 3397