Answer:
50%
Step-by-step explanation:
To calculate the percentage of increase, what we must do divide the two quantities, in this way we will be able to know how bigger they are from each other. So:
9000/6000 = 1.5
Now, we subtract those from 1, which would be 100%
1.5 - 1 = 0.5
therefore the increase was 50%
