Question

Hey guys need a help here....

Answer 1

In the simplest way it should be

N=number of terms in the A.P

N=((a-l)/d)-1

Bcoz

L= a+(n-1)d

If we subtract “a”from “l” we get

L-a = nd-d

And then Divide it by “d” we get ..

(L-a)/d= n-1

Adding one to both the sides we get

((l-a)/d)-1=n