Answer:
Option A is the correct answer.
Step-by-step explanation:
Let the work plow a field be x.
Annmarie can plow a field in 240 minutes.
Rate at which Annmarie can plow[tex]=\frac{x}{240}[/tex]
Gladys can plow a field 80 minutes faster
Time taken by Gladys = 240 - 80 = 160 minutes.
Rate at which Gladys can plow[tex]=\frac{x}{160}[/tex]
If they combine time taken to plow [tex]=\frac{x}{\frac{x}{240}+\frac{x}{160}}=\frac{240\times 160}{240+160}=96\texttt{ minutes}[/tex]
Option A is the correct answer.
