Answer:
14 hours
Step-by-step explanation:
Jack and Ming can togrther tar a roof in 6.16 hours.
In 1 hour they can tar 1/6.16 of the roof.
Ming alone can tar the roof in 11 hours.
So in 1 hour he can tar 1/11 of the roof.
Let the number of hours taken by Jack to tar the roof = x
Then in 1 hour Jack can tar 1/x of the roof.
=> [tex]\[\frac{1}{x}+\frac{1}{11}=\frac{1}{6.16}\][/tex]
=> [tex]\[\frac{1}{x}=\frac{4.4}{61.6}\][/tex]
=> x=14
Jack will take 14 hours to tar the roof alone.
