The number is not less than 20. The number is not greater than 40. The number is not divisble by 2, 3, or 7.THe number is not a prime number. THe sum of the number's digits is not 8.
What's the number?
25
To find the number that satisfies all the given conditions, we need to follow a systematic approach.
1. Start with the range of numbers that fulfills the first two conditions: not less than 20 and not greater than 40. So, we have 20, 21, 22, ..., 39, 40.
2. Exclude the numbers that are divisible by 2, 3, or 7. Among the remaining numbers, we can remove 22 (divisible by 2), 24 (divisible by 2), 26 (divisible by 2), 27 (divisible by 3), 28 (divisible by 2 and 7), 30 (divisible by 2 and 3), 32 (divisible by 2), 33 (divisible by 3), 34 (divisible by 2), 35 (divisible by 5), 36 (divisible by 2 and 3), 38 (divisible by 2), and 40 (divisible by 2 and 5).
3. Among the remaining numbers, we need to remove the prime numbers. Prime numbers are numbers that are only divisible by 1 and themselves. By checking each remaining number (20, 21, 23, 25, 29, 31, 37, and 39), we can eliminate 23 (prime), 29 (prime), 31 (prime), and 37 (prime).
4. Finally, we need to consider the sum of the number's digits. Exclude any numbers that have a sum of digits equal to 8. From the remaining numbers (20, 21, 25, and 39), only 21 has a sum of digits equal to 8 (2 + 1 = 3).
Thus, the number that satisfies all the given conditions is 25.