Yesenia swims laps at a pool. For every 10 laps she swims the backstroke, she swims 15 laps of freestyle. Which ratio shows the number of laps Yesenia swims the backstroke to the number of laps she swims freestyle?

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

The number of chocolate chips in a bag of chocolate chip cookies is approximately normally distributed with a mean of 12611261 chips and a standard deviation of 118118 chips. (a) determine the 2626th percentile for the number of chocolate chips in a bag. (b) determine the number of chocolate chips in a bag that make up the middle 9696% of bags. (c) what is the interquartile range of the number of chocolate chips in a bag of chocolate chip cookies?

Math i have no idea how to do a and b