At tubman middle school there are 7 english teachers and 6 science teachers. if each student takes one english class and one science class, how many possible combinations of teachers are there?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

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.

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.