30 has 8 factors, 1, 2, 3, 5, 6, 10, 15, and 30.
24 has the most factors of all the numbers between 1 and 25. The 8 factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24.
25 it's factors are 1, 5,and 25. That's a number between 12 and 40 that has only 3 factors
25 does.
1 has the least factors.
25
25
There is no such number with "most factors"; if you have a number with a certain number of factors, you can always multiply it by 2, or by 3, etc., to get another number that has even more factors.
The numbers between 10 and 30 that have exactly 5 factors are 16 and 25. The number 16 has factors 1, 2, 4, 8, and 16. The number 25 has factors 1, 5, 25, but since it is a perfect square, it also includes the repeated factor of 5. These are the only two numbers between 10 and 30 that have exactly 5 factors.
21
24 does.
50
These numbers between 1 and 40 have an odd number of factors: 4, 9, 16, 25, 36.