The graph shows the number of gallons of white paint that were mixed with gallons of blue paint in various different ratios:

The title is Mixing Paint. The horizontal axis label is Blue Paint in gallons. The scale is 0 to 16 in increments of 2. The vertical axis label is White Paint in gallons. The scale is 0 to 32 in increments of 4. Plot points at the ordered pairs 2,4 and 4,8 and 6,12.

The number of gallons of white paint mixed with 1 gallon of blue paint is _____