Answer:
Jenny made $144 for 9 hours of work so you divide 144 by 9 and you get 16.
$16 is the amount of money that Jenny makes in an hour. To check if it's correct you multiply 16 by 9 and you should get 144.
So, since the question wants you to find how much she makes for 12 hours of work, you multiply 16 times 12 and you should get 192.
In conclusion, Jenny makes $192 for 12 hours of work.