Answer:
23/12 hours or 1.9167 hours
Step-by-step explanation:
We are told that Sam can clean the pool in 5 hours. This implies 1:5
Also, his coworker Glenn can clean the same pool in 7 hours. This implies 1:7
Since it's the same pool, let's generate a workrate formula.
Thus;
(1/5)x + (1/7)x = 1
Where x is the amount of time used by both of them to clean 1 pool
Simplifying it, we multiply each term by 35 to get;
7x + 5x = 35
12x = 35
x = 35/12
We are now told that One day Sam
started to clean the pool by himself and worked for an hour.
Thus, remaining time after Sam worked 1 hour is; (35/12) - 1 = 23/12 hours
Thus, time they both used to finish cleaning the pool is 23/12 hours
