Find the factor prime or composite 83

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document

The data set represents the ages of players in a chess club. 27, 34, 38, 16, 22, 45, 54, 60. what is the mean absolute deviation of the data set?

X² + 4y² = 36 the major axis runs along: a) y=4x b) x-axis c) y-axis