At a party, 70 people are right -handed and 12 people are left - handed what is the ratio of right - handed people to the total? (reduce your answer to lowest terms ) can someone explain how to do ratio i'll appreciate that

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?

Can you me with this question? i'll reward *30 points i just need with this one question so that i could solve the others. * edit: i originally set up the question to reward 30 points, but for some reason i can only reward 15. if you don't get 30, then i'm sorry. i'm still kind of new to this site

If jklm is a trapezoid, which statements must be true?