Answer:
4 hours.
Explanation:
According to the statement, you know that the amount she earns per week is equal to the first 30 hours for the price per hour that is $4 plus the number of hours over 30 hours multiply for its price that is $6. According to this, you can write the following equation where x is the hours of overtime per week:
4(30)+6x=144
120+6x=144
Now, you can solve for x:
6x=144-120
6x=24
x=24/6
x= 4
According to this, the answer is that Kate will need 4 hours of ovetime per week to achieve her goal.