Question

For an A.P. t_{3 =} 8 and t₄ =12, find the common difference d.

Answer 1

Given:
t₃=8 and t₄=12
Since, t_n=a+(n - 1)d
t₃=a+(3-1)d
8=a+2d… (i)
t₄=a+(4-1)d
12=a+3d … (ii)
Subtracting (i) from (ii), we get
d=4
The common difference is 4.