Simplify : $$ {(7) ^{2} ÷(7^{1\over 2})^{4}}$$

If A's capital is equal to three times of B's capital and if B's capital is equal to four times of C's capital, then the ratio of their capitals is

A train is moving at a speed of 80 km/ h and covers a certain distance in 4.5 hours. The speed of the train to cover the same distance in 4 hours is 

36 people working 8 hours a day can do 3 units of work in 12 days. How many persons are required to do 5 units of that work in 16 days. If they work for 6 hours a day?

A solid sphere of diameter 7 cm is cut into two equal halves. What will be the increase (in cm.²) in the total surface area?

If average of two x and $$1\over x$$ (where x ≠ 0) is A, what will be the average of x³ and $$1\over {x^3}$$?

The length of one side of a rhombus is 6.5 cm and its altitude is 10 cm. If the length of its diagonal be 26 cm, the length of the other diagonal will be : 

1, 3, 5, 7, ………total average of 25^th number  is: