Question

if the common difference of an ap is 3 then find a 20 - 15

Answer 1

Heya !!

d = 3 (given)
We know that,
an=a+(n-1)d
So,a20=a+(20-1)(3)
a20=a+19(3)
a20=a+57

Similarly, a15=a+14d
a15=a+14(3)
a15=a+42

Now,a20-a15=(a+57)-(a+42)
=a+57-a-42
=57-42
=15

Answer 2

Answer:

Step-by-step explanation:

15 is the final ans