Find four numbers in an A.P whose sum is 20 and sum of their squares is 120 .

Find the three numbers in GP whose sum is 13 and the sum of whose squares is 91.

Find three numbers in AP whose sum is -3 and whose product is 8.

Find the three numbers in AP whose sum is 21 and product is 231.

Find two numbers whose sum is 6 and product is 9.

Find two positive numbers whose sum is 15 and the sum of whose squares is minimum.

Find two positive numbers such that their sum is 8 and the sum of their squares is minimum.

Find two numbers whose sum is 24 and whose product as large as possible.

Find two positive numbers whose sum is 16 and the sum of whose Cubes is minimum.

Find the quadratic equation whose sum of the roots of is 2 and sum of their cubes is 98.

The sum of the first four terms of an A.Pis 56. The sum of the last four terms is 112. If its first term is 11, then find the number of terms.