TNT go boom boom boom lol

Can someone me with my hwplz(only the circled ones)

This stem-and-leaf plot represents the heights of the students on ralph’s basketball team. one student’s height is missing from the plot. if the mean height of all the students on the team is 61 inches, what is the missing height? a. 55 in. b. 59 in. c. 61 in. d. 65 in.

Moesha is (3g+1) years old and shanti is twice moesha age. find the sum of the ages of moesha and shanti in 2 years time. how old will shanti be when moeshas age in twice her present age? find how old moesha and shanti were 4 years ago if g= 5