Question
A train travelling at the speed of 72 km/hr crosses
another train, having 20 meters less length and travelling in opposite direction at the speed of 54 km/hr in 6 seconds. If the longer train crosses a platform in 16 seconds, then the shorter train will cross the same platform in how many seconds?Solution
Speed of longer train = 72 Γ (5/18) = 20 m/s
Speed of shorter train = 54 Γ (5/18) = 15 m/s
Let length of longer and shorter trains be βLβ meters and (L β 20) metres, respectively.
According to question,
L + L β 20 = (20 + 15) Γ 6 = 210
2L β 20 = 210
L = 115 metres
So, L β 20 = 95 metres
Let length of platform is βPβ metres
So, P + 115 = 20 Γ 16 = 320
P = 320 β 115 = 205 meters
Desired time = (205 + 95)/15 = 300/15 = 20 seconds
24, 12, 22.5, 45, 157.5, 708.75
Find the wrong number in the given number series.
3, 4, 10, 33, 136, 680
In each of the following number series, one term is wrong. Find the wrong term.
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324, 314, 294, 264, 224, 184
32, 16, 24, 60, 207, 945
124, 186, 375, 930, 2790, 9765
Find the wrong number in the given number series.
65, 91, 130, 182, 286, 429
12, 10, 23, 65, 265, 1289Β
120, 126, 135, 145, 170, 200
- Find the wrong number in the given number series.
60, 75, 101, 150, 210, 285