Question

a) Divide 21 into three parts which are in A.P. such that the product of the last two terms
is 56.
​

Answer 1

We need to divide 21 into three parts in A.P such that the product of the first and second parts is 21.

Let the three parts of AP are a-d, a, a+d.

Sum of these terms is 21.

Divide both sides by 3.

The value of a is 7.

Product of the first and second parts is 21.

Substitute a=7 in the above equation.

Divide both sides by 7.

The value of d is 4. Therefore, the required AP is 3, 7, 11.

#Learn more

Divide 21 into three parts, which will be A.P , such that the product of the first and second parts is 28.

Divide 24 into three parts such that they are in A.P and their product is 440.