PLEASE HELP! Whoever solves it first gets Brainliest!

The circumference of a circle is 5 pi cm. what is the area of the circle?

Which of the following answers is 5/25 simplified? 1/5 5/5 2/5 1/25

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