Question

If 8 times the 8th term of an arithmetic progression is equal to 12 times of 12th term, then find the 20th term of the AP?
1. 2
2. 1
3. 0
4. -1
5. -2

Answer 1

Correct Answer - Option 3 : 0

Calculation:

a8 = a + (8 – 1)d

⇒ a8 = a + 7d

⇒ 8a8 = 8a + 56d

Similarily, a12 = a + 11d

⇒ 12a12 = 12a + 132d

On equating both the equations we will get,

8a + 56d = 12a + 132d

⇒ a = -19d

Now, a20 = a + 19d

⇒ a20 = -19d + 19d = 0