Question

The first and last term of an AP are 5 and 45 respectively. If the sum of all its term is 400, find the common difference and the number of terms.

Answer 1

Step-by-step explanation:

kya gunda banega re Tu. chal yaar itna easy question nahi bana paya

Answer 2

Step-by-step explanation:

a=5, an=45, Sn=400

Sn=n/2*(a+an)

400=n/2*50

n=16

an=a+(n-1)d

45=5+15*d

d=2.25