Question

the sum of a certain number of terms of the A.P. 25,22,19,....is 116.Find the last term​

Answer 1

Answer:

8

Step-by-step explanation:

a=25

d= -3

S=116

$s = \frac{n}{2} (2a + (n - 1)d)$

substituting the values you get a quadratic equation

$3 {n}^{2} - 53n + 232$

$3 {n}^{2} - 24n - 29n + 232$

$(3n - 29)(n - 8)$

since n cannot be fraction, we discard n=29/3

therefore,n=8