Question

find the sum of the following AP 1/2 ,2/3, 7/10 ...... to 15 terms

Answer 1

Answer:

a=1/2 , d=2/3 - 1/2 = 4-3/6 = 1/6 , n=15

Sn= n/2{2a+(n-1)×d}

S15= 15/2 {2×1/2+(15-1)×1/6}

=15/2 {1+14×1/6}

=15/2 (15 + 7/3)

=15/2 (75+7 /3)

=15/2 × 82/3

=5×41 = 205

hope it helps u...!!!