If Jasper installs a floor himself, it will take him 7 hours. Working with Yolanda, it will take them 3 hours. A table showing Rate in part per hour, Time in hours, and Part of Floor Installed. The first row shows Jasper, and has, StartFraction 1 Over 7 EndFraction, 3, and question mark. The second row shows Yolanda and has r, 3, and 3 r.
If they work together, what is the missing value in the table that represents the part of the floor Jasper will install?

StartFraction 1 Over 7 EndFraction times 3.(3)
StartFraction 1 Over 7 EndFraction times r. r
7r
7(3)