Question

The 11th and 13th terms of an A.P. are 35 and 41 respectively its common difference is ..... (a) 38 (b) 32 (c) 6 (d) 3

Answer 1

EXPLANATION.

=> 11th term of an Ap = 35

=> 13th term of an Ap = 41

To find the common difference.

Formula of Nth term of an Ap.

=> An = a + ( n - 1 ) d

=> a + 10d = 35 ........(1)

=> a + 12d = 41 .........(2)

Form equation (1) and (2) we get,

=> - 2d = -6

=> d = 3

put the value of d = 3 in equation (1) we get,

=> a + 10(3) = 35

=> a + 30 = 35

=> a = 5

Therefore,

First term = a = 5.

common difference = d = 3.

option [ D ] is correct answer.