Share

# If the seventh term of an AP is 1/9 and its ninth term is 1/7, find its 63rd term - CBSE Class 10 - Mathematics

#### Question

If the seventh term of an AP is 1/9 and its ninth term is 1/7, find its 63rd term.

#### Solution

Let a be the first term and d be the common difference of the given A.P.

Given:

a_7=1/9

a_9=1/7

a_7=a+(7-1)

d=1/9

=>a+6d=1/9 .........(1)

a_9=a+(9-1)d=1/7

=>a+8d=1/7......(2)

Subtracting equation (1) from (2), we get:

2d=2/63

=>d=1/63

Puttingd=1/63 in equation (1), we get:

a+(6xx1/63)=1/9

=>a=1/63

∴ a_63=a+(63-1)d=1/63+62(1/63)

=63/63=1

Thus 63rd term   of the given A.P. is 1.

Is there an error in this question or solution?

#### Video TutorialsVIEW ALL [6]

Solution If the seventh term of an AP is 1/9 and its ninth term is 1/7, find its 63rd term Concept: Arithmetic Progression.
S