This is it, right? The topic is unclear.
Got it for you.
Let the total amount be 1.
Lie down for x hours every day.
Leave it for y days
The original velocity is 1/xy.
Roads are paved at a certain time and speed.
Spread to three-quarters of the road.
The explanation accounts for three quarters of the total time.
That is to say, it takes three quarters of the total time, which is 3xy/4.
It takes x hours every day.
Total * * * needs 3xy/4x, which means 3y/4 days.
The amount of 1/4 remains.
The paving speed is increased by one eighth, that is, the original speed is multiplied by (1+8/ 1), that is, 9/8xy.
The daily laying time is reduced by one third, that is, the time multiplied by (1- 1/3) is 2x/3.
Remaining road time = remaining quantity/later speed, that is, remaining road time = 1/4 divided by 9/8xy =2xy/9.
Days spent on remaining roads = time spent on remaining roads/time spent every day thereafter, that is, days spent on remaining roads =2xy/9 divided by 2x/3.
That is, the number of days spent on the remaining roads =y/3.
Three-fourths days for paving this road+days for remaining roads = total days.
That is 3y/4+y/3= 13.
So y= 12.