Need help pls I’m taking a test

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319

Which equation represents a line that passes through the point (9, -4) and has a slope of 3/5?

Grandpa ernie is shrinking! over the past 4 years his height decreased by a total of 2.4 cm.it decreased by the same amount each year. what was the change in grandpa ernie's height each year