The 6th term of an A.P. is 18 and the 9th term is 12. The 15th term is equal to

Question

The 6th term of an A.P. is 18 and the 9th term is 12. The 15th term is equal to (A) 0 (B) 1 (C) 2 (D) 3

Tardigrade Admin · Accepted Answer

Let a be the first term and d be the common difference. ∴ a6 = 18 ⇒ a + 5d = 18 ....(i) a9 = 12 ⇒ a + 8d = 12 ...(ii) Solving (i) and (ii), we get a = 28, d = - 2 ∴ a15 = a + 14d = 28 + 14 (-2) = 0

Q. The $6^{t h}$ term of an $A . P$ . is $18$ and the $9^{t h}$ term is $12$ . The $1 5^{t h}$ term is equal to

$0$

$1$

$2$

$3$

Let $a$ be the first term and $d$ be the common difference.
$∴ a_{6} = 18$
$\Rightarrow a + 5 d = 18 .... (i)$
$a_{9} = 12$
$\Rightarrow a + 8 d = 12 ... (ii)$
Solving $(i)$ and $(ii)$ , we get
$a = 28$ ,
$d = - 2$
$∴ a_{15} = a + 14 d$
$= 28 + 14 (- 2)$
$= 0$

Q. The 6th term of an A.P. is 18 and the 9th term is 12. The 15th term is equal to

0

1

2

3

Let a be the first term and d be the common difference. ∴a6​=18 ⇒a+5d=18....(i) a9​=12 ⇒a+8d=12...(ii) Solving (i) and (ii), we get a=28, d=−2 ∴a15​=a+14d =28+14(−2) =0

Q. The $6^{t h}$ term of an $A . P$ . is $18$ and the $9^{t h}$ term is $12$ . The $1 5^{t h}$ term is equal to

$0$

$1$

$2$

$3$

Let $a$ be the first term and $d$ be the common difference.
$∴ a_{6} = 18$
$\Rightarrow a + 5 d = 18 .... (i)$
$a_{9} = 12$
$\Rightarrow a + 8 d = 12 ... (ii)$
Solving $(i)$ and $(ii)$ , we get
$a = 28$ ,
$d = - 2$
$∴ a_{15} = a + 14 d$
$= 28 + 14 (- 2)$
$= 0$