Vii .. (1) 8:10 = (4)/5 = 40 ÷ (50) = (0.8)

(2) There are 25 boys and 20 girls in the school computer group. The number of boys is (1.25 or 5/4) times that of girls. The simplest integer ratio of girls to boys is (4): 5, and girls account for (4/9) of the total number.

(The ratio of 20kg to 0.2t is (110) or 0. 1.

8. Solution 1 24÷(5+3)=3 (hours) 3×5= 15 (hours) 3×3=9 (hours)

Solution 2 5+3=8 24×5/8= 15 (hour) 24×3/8==9 (hour)

9. 150 ton: 60 ton =150: 60:15 =10: 4:1.

10 The age ratio between my father and me is 6:19. The annual salary ratio between my father and mother is 25:16. The monthly salary ratio of mom and dad is 16: 25.