Question

Find
the
sum of first 20 terms of AP 3,7,11, 15 is​

Answer 1

Answer:

820

Step-by-step explanation:

a = 3 , d = 7-3 = 4

s20 = n/2(2a +(n-1)d)

= 20/2(2(3)+(20-1)4)

= 10(6+76)

= 10(82)

= 820 ..

Answer 2

Answer:

820

Step-by-step explanation:

a=3,d=7-3=4

s20=n/2(2a+(n-1)d)

=20/2(2(3)+(20-1)4)

=10(6+76)

=10(82)

=820