Hi, thank you for posting your question here at Brainly.
This question could easily be solved if we knew the time each of them work last week. For educational purposes, let's assume it took each of them 8 hours last week. Then,
Conrad: (1+3/4)(8) = 14 hours
Giovanni: (1+1/3)(8) = 10.7 hours
Sally: (2/3)(8) = 5.3 hours