The plumber charges $50 for the first visit plus $8 per hour of work . if the plumbers total bill is $290 how many hours did he work

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?

I'm confused on this could anyone me and show me what i need to do to solve it.