3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191 those are some prime numbers :)
You may remember the two way relative frequency table where each entry in the table is divided by a total from the table. When each cell is divided by the table total (in this case 240), you get a two way whole table relative frequency. (There are also row and column relative frequency tables.)
Formula:
x + 2(x+1) = 17
x + 2x + 2 = 17
3x + 2 = 17
3x = 15
x = 5
So, the answer is 5 and 6
Hope this helped!