$$ {\sqrt{784}} × \sqrt{6.25} + 56\%\ of\ 450=?+186$$

A pipe of diameter ‘d’ can drain a certain water tank in 40 minutes. The time taken by a pipe of diameter ‘2d’ for doing the same job in: 

A wholesaler had 200 dozen of mangoes. He sold some of these mangoes at 20 % profit and the rest at 10 % profit, so that he made 13 % profit on selling all the mangoes. How many mangoes in dozens) did he sell at 20 % profit? 

The difference of cube between the two numbers is 999. If the numbers are in the ratio of 4: 3, then what is the square of the smaller number?

If (x+y+z)=12, xy+yz+zx=44 and xyz=48, then what is the value of x³+y³+z³=?

The remainder when (15²³ + 23²³⁾ is divided by 19, is  

A man crosses a diagonal of square in two minutes at the speed of 6 km./hr. Find the area of the square-