Sydney and Tori work together to paint a room in 8 hours. Sidney could paint the entire room alone two hours faster than Tori could paint the room alone. Find the time to each person could paint the room alone. Show work. 

33% of college students say they use credit cards because of the rewards program. you randomly select 10 college students and ask each to name the reason he or she uses credit cards. find the probability that the number of college students who say they use credit cards because of the rewards program is (a) exactly two, (b) more than two, and (c) between two and five inclusive. if convenient, use technology to find the probabilities.

Math each whole number with a rational,exponential expression

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?