Q. 43.5( 8 Votes )

# Find the 23^{rd} term of the AP 7, 3, 1, –1, –3, …

Answer :

To Find: 23^{rd} term of the AP

Given: The series is 7, 5, 3, 1, –1, –3, …

a_{1}= 7, a_{2}= 5 and d= 3–5= –2

(Where a=a_{1} is first term, a_{2} is second term, a_{n} is nth term and d is common difference of given AP)

Formula Used: a_{n} = a + (n - 1)d

So put n =23 in above formula, we have

a_{23}= a_{1} + (23 - 1)(–2) = 7– 44 = –37

So 23^{rd} term of AP is equal to –37.

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