38 of them.
61, 67, 71, and 73
75 - 1 = 74 numbers between 1 and 75. Divide 74 by 2 = 37 even numbers.
The odd numbers between 70 and 90 are 71, 73, 75, 77, 79, 81, 83, 85, 87, and 89. We know right away that 75 and 85 are composite, since they're divisible by 5. 81 is composite since it is the square of 9. 77 is obviously divisible by 11, so it, too, is composite. 87 is divisible by 3 since 8 + 7 = 15, which is divisible by 3. Therefore, and trust me, I double-checked the rest, 75, 77, 81, 85, and 87 are the composite, odd numbers between 70 and 90.
All of the whole numbers between 50 and 75 are composite numbers, except 53, 59, 61, 67, 71, and 73.
The sum of all prime numbers between 60 and 75 is 272
These two odd numbers are 39 and 65. Both are between 25 and 75, and their GCF is 13.
73 75 77
13 if you include the '75', 12 if you don't.
272
The halfway point between 60 and 90 can be found by calculating the average of the two numbers. To do this, add 60 and 90 together to get 150, then divide by 2 to get 75. Therefore, 75 is the number that is halfway between 60 and 90.
39 and 65
11 + 13 + 15 + 17 + 19 = 75
38 of them.
All the numbers are odd numbers.
The GCF of any two odd numbers is also odd.
Only whole numbers are even or odd, and the square root of 75 is not a whole number.