Question

How many multiples of 4 lie between 10 and 250 ?

Answer 1

First multiple of 4 between 10 and 250=12.

Also, the last number which is multiple of 4 between 10 and 250=248
Then, the series will be 12,16,20……….248.
It is a arithmetic series with first term a=12, common difference d=4

and last term an= 248.

We know that the nth term of an AP is given by

an=a+(n−1)d

⇒ an=248
⇒248=12+(n−1)×4
⇒(n−1)×4=248–12
⇒n−1=2364
⇒n=59+1

∴n=60.

So, 60 multiples of 4 lie between 10 and 250.