Question

If the common difference of an AP is 3, then t20 – t15 is ​

Answer 1

Answer:

t20 - t15 = 15.

Step-by-step explanation:

t20 = a+(20-1)d

t20 = a+19d

t15 = a+(15-1)d

t15 = a+14d

Given, Common difference(d) = 3

t20 - t15 = a+19d-(a+14d)

= a+19d-a-14d

= 5d = 5×3

= 15.

Hope this helps you..