I do not agree . 25% of his hourly pay equals $ 2.25
.25 * 9 = 2.25
9+2.25=11.25
He wants his hourly pay to be $12 .
12-9 = $3
so, he needs his hourly pay to be increased by $3 to reach his goal.
$3 is 1/3 of his current hourly pay .
1/3 = 33%
now .33*9= $ 3
* means times ( multiplied by)
Hope that this helps !