Sequence And Series Question 18
Question: If the $ 9^{th} $ term of an A.P. is 35 and is 75, then its $ 20^{th} $ terms will be
[RPET 1989]
Options:
A) 78
B) 79
C) 80
D) 81
Show Answer
Answer:
Correct Answer: B
Solution:
$ T_9=a+8d=35 $ and $ T_{19}=a+18d=75 $ Solving the equations, we get $ d=4 $ and $ a=3 $ Hence $ 20^{th} $ term of A.P. $ a+19d=3+19\times 4=79 $ .
BETA
