Question

find sum of 2,13/4,9/2.... upto 20 term​

Answer 1

Answer:

S20 = 277.5

Step-by-step explanation:

a=2

d=13/4 -2

LCM =4

13-8/2 = 5/4

n=20

Sn = n/2 {2a + (n-1)d }

S20 = 20/2 { 2*2 + 19*5/4}

= 10{ 4+ 95/4 }

=10*4 + 10 *95/4

=40+ 475/2

LCM = 2

= (80 + 475)/ 2

=555/2

=277.5