Question

How many multiples of 4 lie between 10 and 205?

Answer 1

We need to find the number of multiples of 4 between 10 and 205.
So, multiples of 4 give the sequence 12, 16, ..., 204
a = 12, d = 4 and an=204">a_n = 204
Using the formula an=a+n-1d">a_n = a + (n−1)d
Plugging values in the formula we get
204=12+n-14204=12+4n-44n=196n=49">204 = 12 + (n−1)4
204 = 12 + 4n − 4
4n = 196
n = 49
Thus, there are 49 multiples of 4 between 10 and 205.