Question

Which term of the AP 25, 20, 15, ... is the first negative term?

विकल्प

• 10th

• 9th

• 8th

• 7th

Answer 1

7th

Explanation:

Let T_n < 0.

Then, 25 + (n – 1) × (–5) < 0. 

∴ 30 < 5n

⇒ 5n > 30 

⇒ n > 6

So, the required term is 7th.