Find the fraction of the work completed by both Bunmi and Dele in 2 hours. Then subtract this from 1 to find the fraction of work left.unmi’s rate: \(\frac{1}{5}\) of the plot per hourele’s rate: \(\frac{1}{4}\) of the plot per hourombined rate: \(\frac{1}{5} + \frac{1}{4} = \frac{9}{20}\) of the plot per hour
In 2 hours, they complete: \(2 \times \frac{9}{20} = \frac{9}{10}\) of the plotraction of work left: \(1 - \frac{9}{10} = \frac{1}{10}\)