Which pair of numbers is relatively prime? A. 7 and 21
B. 4 and 15
C. 6 and 9
D. 9 and 27

Atemperature of 1.64◦f corresponds to answer in units of ◦c.

Math question.. plz me .. best answer all

Randy and trey take turns cleaning offices on the weekends. it takes randy at most 4 hours to clean the offices. it takes trey at most 6 hours to clean the offices. what is the greatest amount of time it would take them to clean the offices together? 2.4 hours 2.5 hours