If the common difference of an AP is 5, then what is a18 – a13?(A)

1.	If the common difference of an AP is 5, then what is a18 – a13?(A) 5 (B) 20 (C) 25 (D) 30
Answer» (C) 25 Explanation: Given, the common difference of AP i.e., d = 5 Now, As we know, nth term of an AP is a_{n =} a + (n – 1)d where a = first term a_n is nth term d is the common difference a₁₈ -a_{13 =} a + 17d – (a + 12d) = 5d = 5(5) = 25

If the common difference of an AP is 5, then what is a18 – a13?(A) 5 (B) 20 (C) 25 (D) 30

Answer»

(C) 25

Explanation:

Given, the common difference of AP i.e., d = 5

Now,

As we know, nth term of an AP is

a_{n =} a + (n – 1)d

where a = first term

a_n is nth term

d is the common difference

a₁₈ -a_{13 =} a + 17d – (a + 12d)

= 5d

= 5(5)

= 25