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.
Call the price of the bike before mark up 'x', then we have:
x + 0.25x = 210
1.25x = 210
x = 168
Therefore, the bike cost $168 before 25% price increase.
The first graphed rational number is at the middle of -2 and -1, thus the number represented is

The second graphed number is five out of six places from from 0 to 1, thus the number graphed is

The difference between the two numbers can be represented as

or

To find the difference,

Also,