10, 12, 14 , (16)
Nine of them.
9 of them.
These numbers between 1 and 40 have an odd number of factors: 4, 9, 16, 25, 36.
There are seven square numbers (1, 4, 9, 16, 25, 36, and 49) between 0 and 50.
9 + 7
90
There are 14 such numbers between 16 and 189.
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 two square numbers that have a difference of 9 are 25 and 16. This can be expressed as (5^2 = 25) and (4^2 = 16). The difference between them is (25 - 16 = 9).
9 and 16
9
4, 9, 16, 25, and 36 are the square numbers between 1 and 40.
4, 9, 16 and 25
4, 9, 16, 25
10, 12, 14
1, 4, 9, 16, 25, 36
18