What will come in place of question mark (?) in the following number series ?
For the following questions answer them individually
Two pipes can fill a tank in 10 hours and 16 hours respectively. A third pipe can empty the tank in 32 hours. If all the three pipes are opened simultaneously then in how much time the tank will be full ? (in hours)
A merchant bought some goods worth Rs. 6000 and sold half of them at 12% profit. At what profit per cent should he sell the remaining goods so as to make an overall profit of 18%?
A and B are two numbers. six times the square of B is 540 more than the square of A. If the respective ratio between A and B is 3 : 2, what is the value of B?
The perimeter of a rectangle whose length is 6rn more than its breadth is 84 m. What would be the area of a triangle whose base is equal to the diagonal of the rectangle and whose height is equal to the length of the rectangle ? (in m )
56 workers are finish a piece of work in 14 days. If the work is to be completed in 8 days, how many extra workers are required?
A train 210m long takes 6 seconds to cross a man running at 9 km/hr in a direction opposite to that of the train. What is the speed of the train? (in kmph).