18
Counting 0 as a number, it's 20. Not counting 0, it's 30.
30
If you are including 10 and 30 there are 11 even numbers. If you are not counting 10 and 30 there are 9 even numbers between 10 and 30.
The answer will depend on how many digits there are in each of the 30 numbers. If the 30 numbers are all 6-digit numbers then the answer is NONE! If the 30 numbers are the first 30 counting numbers then there are 126 combinations of five 1-digit numbers, 1764 combinations of three 1-digit numbers and one 2-digit number, and 1710 combinations of one 1-digit number and two 2-digit numbers. That makes a total of 3600 5-digit combinations.
18
153
Counting 0 as a number, it's 20. Not counting 0, it's 30.
The product of the first three prime numbers (2, 3, and 5) is 30.
30
None of them. All counting numbers are either odd or even.
None. All counting numbers are even or odd.
The first three prime numbers are 2,3, and 5. Their product is 2x3x5 =30. Note, 1 is not considered a prime, so we do not use it.
30 - 31 = -1
If a timer is counting down from 30, it doesn't actually count 30. It starts counting at 29. If you are counting up to 10, you wouldn't count the number that you are counting from. If you counted 0, you would actually be counting 11 numbers.
The natural numbers are the counting numbers. Therefore, the natural numbers less than 31 are the numbers from 1 to 30.
If you are including 10 and 30 there are 11 even numbers. If you are not counting 10 and 30 there are 9 even numbers between 10 and 30.