The value of a precious gem stone has increased at a rate of 105% each year. if the gem"s value started at $10 in 1995 ,how much is it worth in 2014?

Twelve friends shared 8 small pizzas equally. how many pizzas did each person get?

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.

How is working backward similar to solving an equation?