2. given A: B = 1/3: 2/5 and B: C = 3: 7, then A: B: C = (5: 6: 14).
3. For two cubes, the ratio of side length 1: 2, the ratio of surface area (1: 4) and the ratio of volume (1: 8).
4. Xiao Wang walked more than Xiao Zhang 1/4, and Xiao Zhang walked more than Xiao Wang110, and the walking speed ratio between them was (55: 40).
5. The radius of a big circle is three times that of a small circle, the ratio of the circumference of the big circle to the small circle is (3: 1), and the ratio of the area of the small circle to the big circle is (1: 9).