Question

to build a road, the plan is to build 80 meters per day, which takes 20 days to complete. if it is to be completed 4 days ahead of schedule, then more meters must be built per day compared to the original plan.

Explanation:

Step1: Calculate total project length

Total length = Daily length × Days
$80 \times 20 = 1600$ meters

Step2: Calculate new project duration

New days = Original days -提前天数
$20 - 4 = 16$ days

Step3: Calculate new daily build length

New daily length = $\frac{\text{Total length}}{\text{New days}}$
$\frac{1600}{16} = 100$ meters

Step4: Calculate daily difference

Difference = New daily length - Original daily length
$100 - 80 = 20$ meters

Answer:

20