Question

If the nth term of an A.P. is 7n − 4, then the common difference of the A.P. is ______.

Options

• 7

• 7n

• −4

• 4

Answer 1

If the nth term of an A.P. is 7n − 4, then the common difference of the A.P. is 7.

Explanation:

Given,

T_n = 7n − 4

T₁ = 7(1) − 4 = 7 − 4 = 3

T₂ = 7(2) − 4 = 14 − 4 = 10

T₃ = 7(3) − 4 = 21 − 4 = 17

Common difference (d) = T₃ − T₂ = T₂ − T₁

= 17 − 10 = 10 − 3

= 7