Question

17. 15th term of AP 10, 7, 4, ...
is
o -52
o -32
o 32​

Answer 1

Step-by-step explanation:

Clearly, the given sequence is an AP with first term a=3 and common difference d=7.

Let the n

th

term is 84 more than its 13

th

term.

⇒a

n

=a

13

+84

⇒a+(n−1)d=(a+12d)+84

⇒(n−1)d=12d+84

⇒(n−1)7=12×7+84

⇒(n−1)7=7(12+12)

⇒n−1=24

⇒n=25

Therefore 25

th

term is required term.