Correct Answer - Option 1 : 2 : 3
Calculation:
⇒ 3rd term = a + 2d
⇒ 7th term = a + 6d
⇒ 17th term = a + 16d
⇒ (a + 6d)2 = (a + 2d) × (a + 16d)
⇒ By solving 6ad = 4d2 Since d > 0
⇒ 6a = 4d
⇒ a/d = 2/3
∴ The required result will be 2/3.
nth terms of arithmetic progression = a + (n - 1) × d
Where a = First term, and d = Common difference