What is 9/21 in simplest form

Add 1/7 + -1/7 your answer should be reduced to its smallest form and should not be an improper fraction

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

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.