When a number is divided by 4, the quotient is 28. What is the number?

Which is next in the series given below? 5,16,49,104,

If the diameter of a circle is increased by 100%, its area is increased by:

There are 850 students in a school. Find the number of boys if the number of girls is 56 less than the boys.

If a+b+c=0;what is(b+c)(b-c)+a(a+2b)