Question

The $9^{th}$ term of an A.P is 449 and ${449}^{th}$ term is 9. The term which is equal to zero is

• A. 457th
• B. 458th
• C. 459th
• D. 454th

Answer 1

The correct option is B

458th

Using formula we get the value of a and d

Again from $t_n=a+(n-1)d$

$t_9=449$

a + (9-1) d = 449...................(1)

Now, $t_{449}=9$

a + (449-1) d = 9

a + 448d = 9...........................(2)

Solving both equations we get, d = -1, and a = 457

Let $p^{th}$ term of A.P = 0

a + (p-1) d = 0

457 + (p-1) (-1) = 0

p = 458