What do we use mathematical induction for?

Sasha drank 8 bottles of water everyday for a week. how many bottles of water did she drink in total?

Aboard 60 in. long is cut two parts so that the longer piece is 5 times the shorter. what are the length of the two pieces?

Nicole is making carrot bread she needs 5 cups of carrots for 2 cups of sugar.what is the ratio of cups of sugar to cups of carrots that nicole will need? write the ration in three different ways