Two pipes can full a tank in 10 h and 16 h respectively. Athird pipe can empty the tank in 32 h. If all the three pipesfunction simultaneously, then in how much time the tankwill be full? (in hours)

7.

A merchant bought some goods worth ` 6000 and sold halfof them at 12% profit. At what profit per cent should he sellthe remaining goods to make and overall profit of 18%?

8.

A and B are two numbers. 6 times of square of B is 540 morethan the square of A. If the respective ratio between A andB is 3 : 2, what is the value of B?

9.

The perimeter of a rectangle whose length is 6 m more thanits breadth is 84 m. What would be the area of a trianglewhose base is equal to the diagonal of the rectangle andwhose height is equal to the length of the rectangle? (in m2)

10.

56 workers can finish a piece of work in 14 days. If the workis to be completed in 8 days, then how many extra workersare required?