Subtract the blue caps:
25-11 = 14 caps are either white or green.
Let green = X
white = X +2
Green + white = 14:
x + x +2 = 14
Combine like terms:
2x +2 = 14
Subtract 2 from both sides:
2x = 12
Divide both sides by 2:
x = 6
There are 11 blue caps, 6 green caps and 8 white caps.