Solution: If Party A uses X days and Party B uses x-20 days (according to the number of days x the amount of money per day = the total amount of money).
40x= 120X(x-20)
40x= 120x-2400
80x=2400
x=30
B: 30-20= 10 (days)
Without the maintenance price of each set of tables and chairs, we can know how many sets of tables and chairs Party A and Party B maintain every day.
2) Scheme 1:
Nail repair cost: 40X30= 1200 (Yuan) Quality Supervision:10x30 = 300 * * Cost: 1200+300= 1500 (Yuan).
Option 2:
Second maintenance requirements:120x10 =1200 (yuan) Quality supervision:10x10 =100 * * Cost:1200+.
Option 3:
1, daily workload of Party A and Party B * * *:1/30+10 = 2/15.
2. Days required for Party A and Party B to cooperate together: 1 divided by 2/ 15=7.5 (days).
A: 40X7.5=300 yuan; B: 120X7.5=900 yuan; Quality Supervision: 10X7.5=75 yuan.
Supply and demand price: 300+900+75= 1275 (yuan)
1500 > 1300 > 1275
Option 3 saves money and time.
Note: Personally, I think each set of tables and chairs is short of repair price.