What is the mean most useful in describing a set of data

For a field trip to the zoo, 4 students rode in cars and the rest filled nine busess. how many students were in each bus if 472 students were on the trip

Solve this riddle: i am an odd number. i an less than 100. the some of my digit is 12. i am a multiple of 15. what number am i?

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great