It will take 48 hours of work to complete the garden.The garden must be finished in 3 days.
Each gardener works for 6 hours per day.
How many gardeners are needed?
In 3 days each grdener will put in 18 hours
2 gardeners will work 36 hours
3 gardeners will manage 54 hours...... so I suggest 3 gardeners to make the 3 day deadline