Jenny has 15 dollars. she buys 2 books that cost $m each. how much does she have left?

Aproduction manager test 10 toothbrushes and finds that their mean lifetime is 450 hours. she then design sales package of this type of toothbrush. it states that the customers can expect the toothbrush to last approximately 460 hours. this is an example of what phase of inferential statistics

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.

What adds to be the bottom number but also multiplies to be the top number with 8 on the bottom and 15 on top