The ratio of girls to boys in Jaime's chorus is 2 to 4. If there are 25 girls in her chorus, how many boys are there? *

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

Money off coupons have been circulated to 300 households. only 2/5 of these were redeemed (used) in the local supermarket to get a free shampoo. what fraction of coupons were unused? (ps: write how you got the answer)