Question

In an Ap the 7th term is twice of 4 in ap of 2 and 12 th term is 3twice of more in ap of 4 so find the AP

Answer 1

Let a1,a2,a3 ,.........,a7 are in a.p. whose common difference is d

a4 = 3a1

a1 + 3d = 3a1

3d = 2a1

a7 = 2a3 + 1

a1 + 6d = 2a1 + 4d + 1

2d = a1 + 1

4a1/3 = a1 + 1

a1 = 3

d = 2