Question

How many multiples of $8$ are between $100$ and $500$?

Answer 1

50

Explanation:

The smallest multiple of 8 in this range is 13 ∙ 8 = 104, and the largest is 62 ∙ 8 = 496. The number of multiples of 8 in this range is the same as the number of numbers in the list

13, 14, 15, ...,60, 61, 62.

To count these, we subtract 12 from each, obtaining the new list

1, 2, 3, ..., 48, 49, 50,

which clearly contains 50 integers. There is one number in the original list for each number in the revised list, so the original list has 50 numbers in it, and there are 50 multiples of 8 between 100 and 500.

Answer 2

There are 50 multiples of 8 between 100 and 500

Explanation:

1. We need to find out the multiple of 8 closest and higher than 100.

......80, 88, 96, 104, 112, 120..... It's 104

2. We need to find out the multiple of 8 closest and lower than 500.

....480, 488, 496, 504, 512, 520......It's 496

3. Now, we use 104 and 496, this way:

(496 - 104)/8 + 1 =

392/8 + 1 =

49 + 1 = 50

There are 50 multiples of 8 between 100 and 500