time-efficient workout (Score 1)

The best option I see is to work out efficiently. Most of the popular stuff wastes your time.

For strength-training, avoid isolation-exercises. They are designed to train as few muscles as possible. Unfortunately the design is successful, they train as little as possible. Prefer compound-exercises that train many muscles in one go.

For fat-loss, long cardio-workouts are overrated. Short, intense workouts save lots of time and even work better. The Tabata-protocol works pretty well with workouts of just 4 minutes (8 intervals of 20 seconds of intense exercise followed by 10 seconds of rest) and has a scientific study to back up that claim.

One possible workout would be a regimen of push-ups and pull-ups for strength and warm-up followed by five minutes of kettlebell-swings (possibly in Tabata-style intervals) plus a gentle cool-down. The whole thing is over in 10 or 12 minutes and will do wonders if done about three or four times a week.