2/3 : 7/9 = 2/3 × 9/7 = 6/7.
6 : 3/5 = 6 × 5/3 = 2 × 5 = 10.
4 1/2 : 3 3/4 = 9/2 × 1/3 × 3/4 = 9/8.
20/21 : 15 = 4/21 × 1/3 = 4/63.
2/3 : 7/9 = 2/3 × 9/7 = 6/7.
6 : 3/5 = 6 × 5/3 = 2 × 5 = 10.
4 1/2 : 3 3/4 = 9/2 × 1/3 × 3/4 = 9/8.
20/21 : 15 = 4/21 × 1/3 = 4/63.