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Question
How many multiples of 4 lie between 10 and 205?
Solution
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">an = 204
Using the formula an=a+n-1d">an = 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.
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