Question

The 17th term of AP is 5 more than twice its 8th term. If the 11th term of the AP is 43, find its nth term.

Answer 1

Correct Answer - `T_(n) = (4n-1)`
`T_(17) = 2T_(8) + 5 rArr a + 16d = 2(a+7d) +5 rArr a -2d = -5. " "…(i)`
Also, a +10d = 43.
Solve (i) and (ii), we get a = 3 and `d = 4. " "..(ii)`