Question

as:
If the nth term of an A.P. is 5+2n, the sum of first 20 terms is
c) 525
a) 485
b) 520​

Answer 1

Answer:

520

Step-by-step explanation:

a nth=5+2n

a1=5+2=7

a2=5+4=9

d=9-7=2

now by applying the formula we get the answer 520

Answer 2

Answer:

the correct answer is 3150