A it takes one person to do it 104 days. 104 ÷ 7 = 14 ...6? I worked 6× 14+6 = 90 days.
A's work efficiency? 1/90
Team b works for five days and has two days off? (? 7-day cycle? No work for 2 days in a cycle)
It takes 82 days for Party B to complete 82 ÷ 7 = 1 1 ... 5 jobs? 5× 1 1+5=60
B's work efficiency is 1/60?
Two teams working together? The working efficiency of a cycle is 6×1/90+5×1/60 = 3/20.
1 ÷ 3/20 = 6 ...2/202/20 ÷ ( 1/90+ 1/60) = 1/ 10 ÷ 1.
6× 7+3.6 = 45.6 days
June 30th? July 3 1 day? 45.6-3-31=1.6 days, that is, 12 was completed in the afternoon of August.
1.？ As shown in the figure: