45
45, 63, 81, 99, 117
six 37 39 41 43 45 47
All of the odd numbers between 11 and 99 inclusive are two digit numbers that are not multiples of 2. There are 45 of them.
There are 20 odd numbers in 40.
There are 45 such numbers.
45
45 of them.
31, 33, 35, 37, 39, 41, 43 & 45 = eight odd numbers !
45
There are ninety 2-digit numbers all together. 45 of them are odd numbers. The other 45 of them are even numbers.
Count how many of the numbers are odd. If an odd number of them are odd, then their sum is odd. If an even number of them are odd, then their sum is even.
odd numbers between 25 and 45 inclusive are 25 27 29 31 33 35 37 39 41 43 45
5*9= 45
45
The GCF of any two odd numbers is also odd.
Go through each of the numbers, and count how many of them are odd. If you count an odd number of them, then their sum is odd. If you count an even number of them, then their sum is even.