The second question: (86-16) ÷ (1-4/9+1) = 45 (yuan)-a; 86-45=4 1 (yuan) -B
The third question: (1-3/7) ÷ (1-9/13) =13/7; 200÷( 1+ 13/7)=70 (yuan)-brother;
200-70= 130 (yuan)
The fourth question:1÷ (9+1) =110; 3÷(3+22)=3/25; 1÷ (3/25-110) = 50 (person)