Question

If the first term of an A.P. is a and nth term is b, then its common difference is
A. b-a/n+1
B. b-a/n-1
C. b-a/n
D.b+a/n-1

Answer 1

Answer:

B. b-a/n-1... ........ .

Answer 2

B. b-a/n-1

Step-by-step explanation:

Let a be the first term and L be the last term of an AP.

We know that L = a + (n-1)d where d is the common difference and n is the number of terms.

L - a = (n-1) d

Therefore d = L - a/ n-1.

Given last term is b, we get d = b-a/n-1.

Option B is the answer.