Question

For an A.P.a=3,d=4,find S20

Answer 1

ur answer is solved above

Answer 2

Answer :-

Given :-

First term (a) = 3

Common difference (d) = 4

To Find :-

20 terms (S 20)

Solution :-

$\large{\star{\boxed{\boxed{an \:=\: a + (n - 1)d}}}}$

Putting values

S 20 = 3 + (20 - 1) 4

S 20 = 3 +(19) 4

S 20 = 3 + 76

S 20 = 79