Question

Find the sum of first 24 terms of an AP whose n th term is given by an =3 +2n

Answer 1

Answer:

672

Step-by-step explanation:

an = 3 + 2n

now put n = 1,2,3,...

a1 = 3 + 2(1)

a2 = 3 + 2(2)

a3 = 3 + 2(3)

Thus the terms of the AP are 5,7,9,...

here a = 5 and d = 2

S24 = 24/2 [ 2 × 5 + ( 24 - 1) ]

= 12 [ 10 + 46]

= 12 × 56

= 672