Question

What is the sum of first 20 term of an A.P a=4 and T20 =36

Answer 1

Answer:

400

Step-by-step explanation:

a = 4

20 th term or the last term for finding the sum=36

number of terms=20

sum of n terms =

a= first term=4

l = last term= 36

and n = no.of terms = 20

after substituting the values

sum = (4+36) x 20/2

40 x 10 = 400