Question

Insert 4 numbers between 2 and 22 such that the resulting sequence is an A.P.

(a) 4, 8, 12, 16

(b) 5, 9, 13, 17

(c) 4, 10, 15, 19

(d) 6, 10, 14, 18

I have been asked this question in a job interview.

This is a very interesting question from Arithmetic Progression(A.P.) topic in division Sequences and Series of Mathematics – Class 11

Answer 1

The correct choice is (d) 6, 10, 14, 18

Easy explanation: Let A.P. be 2, A1, A2, A3, A4, 22.

=>a=2 and a6 = a+5d = 22 => 2+5*d=22 => d=4.

A1 = a2 = a + d = 2 + 4 = 6.

A2 = A1 + d = 6 + 4 = 10.

A3 = 10 + 4 = 14.

A4 = 14 + 4 = 18.