Question

If a, a – 2 and 3a are in AP, then what is the value of a.

Answer 1

Answer:

Since a, a-2 and 3a are in AP

∴2(a−2)=a+3a

⇒2a−4=4a

⇒2a=−4

⇒a=−2

Answer 2

Answer:

Since a, a – 2 and 3a are in AP, so common difference is same.

Therefore, a - 2 - a = 3a - a + 2

- 2 = 2a + 2

2a = - 4

a = - 2.