Question

Between 20 and 28 students signed up for the chess club. The students could not be divided exactly into groups of 2,3,4 or 5. How many students signed up for the chess club? Show your work.

Answer 1

It is 23, because :
23/2 =11,5
23/3 ≈ 7,67
23/4 = 5,75
23/5 = 4,6

I hope to have helped you ! :)

Answer 2

The number is in between 20 and 28, but is not divisible by 2, 3, 4, or 5. So, 20, 22, 24, 26, 28 are removed because it is divisible by 2. We can remove 21 and 27 because those numbers are divisible by 3. So now we have 23 and 25 remaining. But 25 is divisible by 5, so the number of students in the chess club is 23. Your answer is 23.