1 9 = 10 80x 1/ 10 = 80

Page 47: 1. The number of girls is 4/5 of that of boys, 5/9 of that of boys and 4/9 of that of girls. Xiaoming's weight is 9/8 of Xiaoxing's, Xiaoxing's weight is 8/9, Xiaoxing's weight is lighter than Xiaoming's 1/9. 2. column equation: solution: there are x black rabbits. 7/5x=35 x=35*5/7 x=25 A: There are 25 black rabbits. First, find out that "a fraction of white rabbits are black rabbits" and then answer 7/5 divided by 1=5/7 35*5/7=25 A: there are 25 black rabbits, and 3800 divided by (9 1)= 8.