Question

16. Find the 15th term of the A.P. with second term 11 and common difference 9.​

Answer 1

Answer:

The 15th term is 128

Step-by-step explanation:

It is given that,

t2= 11

d= 9

First to find,

a=?

Using formula,

tn= a+(n-1)d

put n=2,

t2= a+(n-1)×d

11= a+(2-1)×9

11=a+ 1× 9

a=11-9

We get a=2

Now,

tn= a+(n-1)d

put n= 15

t15= a+(15-1)d

t15= 2+ (15-1)×9

t15= 2+ 14×9

t15= 2+ 126

t15= 128

Hence, 15th term is 128