A father and his son are waiting at a bus stop in the evening. There is a lamp post behind them. The lamp post, the father and his son stand on the same straight line. The father observes that the shadows of his head and his son's head are incident at the same point on the ground. If the heights of the lamp post, the father and his son are 6 metres, 1.8 metres and 0.9 metres respectively, and the father is standing 2.1 metres away from the post, then how far (in metres) is the son standing from his father?
Correct Answer : D
If 9 engines consume 24 metric tonnes of coal, when each is working 8 hours a day; how much coal will be required for 8 engines, each running 13 hours a day, it being given that 3 engines of the former type consume as much as 4 engines of latter type.
The distances from A to B, B to C and C to D, are 12 kms. each. A man runs from A to B at a speed of X kms/hour. After reaching B, he rests for X hours and runs from B to C at double the previous speed. At C he rests for 2 X hours and runs from C to D at double his speed from B to C. He reaches D in 16 hrs after starting from A. Then a possible value of X is
Pipe A can fill in 20 minutes and Pipe B in 30 mins and Pipe C can empty the same in 40 mins.If all of them work together, find the time taken to fill the tank