What will be come in place of question mark(?) in the following number series?
14, 8, 7 , 11.5, 22, ?

A man spends  $${1\over 3}$$ of his income on food,   $${2\over 5}$$  of his income house rent and   $${1\over 5}$$ of his income on clothes. If he still has Rs. 400 left with him, his income is: 

What is the area of an equilateral triangle having altitude equal to $$5\sqrt{3}$$cm.

From the top of a lamp post of height x metres, two objects on the ground on the same side of it (and in line with the foot of the lamp post) are observed at angles of depression of 30° and 60°, respectively. The distance between the object is $$ {32{\sqrt{3}{\ meter}}}$$. The value of  x is:

If the volumes of two cubes are in the ratio 27 : 64 and then the ratio of their total surface area is 

What is compound interest on a sum of Rs. 37,500 for $$ {1{1\over 3}}$$ years at a rate of 12 % per year. If the interest is compounded 8 monthly?

Anu invested Rs. 15000 at the rate of interest 10% p.a. for one year. If the compound interest is compounded at every six months, what amount will Anu get at the end of the year?

The interior angle of a regular polygon exceeds its exterior angle by $$90^0$$. The number of sides of the polygon is: