Question

Jessica and Franklin are volunteering to paint one of their community member’s fences for service hours. If Jessica could complete the job in 6 hours and Franklin could complete the job in 4.5 hours, how long would it take them to complete the job together, to the nearest minute?

Answer 1

$\frac{1}{t} = \frac{1}{6} + \frac{1}{4.5} = \frac{3+4}{18} = \frac{7}{18}$
t=18/7=2.57 hour =154 min

Answer 2

2.57 hours approximately