Question

Two AP’s have the same common difference. The first term of one of these is -1 and that
of the other is -8. Then the difference between their 4th terms is

Answer 1

First AP a= -1

second AP a'= -8

first fourth term - second AP fourth term

a+3d - a'+3d

-1+3d - (-8)+3d

-1+3d+8+3d

7+6d

d= -7/6