Question

___ multiples of 4 lie between 10 and 250.

Answer 1

The first multiple of 4 which lies between 10 and 250 is 12.

The last multiple of 4 which lie between 10 and 250 is 248.

Therefore, AP is 12, 16, 20... 248
a = 12 and d = 16 - 12 = 4

Using formula $a_n=a+(n-1)d$, to find $n^{th}$ term of arithmetic progression, we can say that

$248=12+(n-1)\left(4\right)$

$\Rightarrow 236=4(n-1)$

$\Rightarrow n-1=\frac{236}{4}=59$

$\Rightarrow n=59+1=60$
It means that 248 is the ${60}^{th}$ term of AP. In other words, we can say that there are 60 multiples of 4 which lie between 10 and 250.