Explanation:

Alright, let’s get straight to it.

- The original work: 16 people × 6 hours/day × 10 days = 960 total man-hours for the whole job.

- You want to find out how long it takes for 24 people doing 8 hours/day to finish 80% of this.

- 80% of 960 man-hours is 768 man-hours.

Now, 24 people × 8 hours/day = 192 man-hours in one day.

768 ÷ 192 = 4 days.

So, option 1 (“4”) is the answer.

Here’s how the options stack up:

- Option 1: 4   ? this is correct.

- Option 2: 3 (too little, doesn’t match the calculation)

- Option 3: 6 (too much time)

- Option 4: 8 (way off)