Simplify this expression.
2u/3u

At the many chips cookie company they are serious about the number of chocolate chips in their cookies they claim that each cookie hasn't c chips. if their claim is true there will be 200 chips in 10 cookies

How do i do this? i don’t understand

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?