Pls help me nobody ever wants to 6th grade math

WILL MARK BRAINLIEST
The number of students in 10 kindergarten classes is shown below
20, 18, 21, 18, 22, 24, 18, 23, 23, 24,

What is the median number of students in the kindergarten classes?

What number of students describes the first quartile

what number of students describes the third quartile

what number of students describes the interquartile range