Question

find the 15th term from the end of the a.p.;3,5,7,9,..,201;

Answer 1

Reversing the order- AP = 201,..........9,7,5,3
a = 201,
d= -2,( 3-5 = -2)
n=15(15th term)
a15 = a + 14d
       = 201 + 14(-2)
       =173


           

Answer 2

The 15th term from the end is 173.

Given:

3,5,7,9,..,201

To find:

The 15th term from the end

Solution:

We will have to reverse the given A.P. to determine the required term from the end.

The A.P. becomes 201, .., 9, 7, 5, 3.

The first term, a=201

The common difference, d=7-9= -2

Now, the 15th term is as follows-

The 15th term=a+(15-1)d

=a+14d

=201+14(-2)

=201-28

=173

Therefore, the 15th term from the end is 173.