Verified answer

2 7/9 * 15 = (2 * 9 + 7)/9 * 15 = 25/9 * 15 = (25*15)/9 = 125/3 = 41 2/3

28 * 1 3/4 = 28 * (1 * 4 + 3)/4 = 28 * 7/4 = (28*7)/4 = 7 * 7 = 49

1 3/5 * 2 1/2 = (1 * 5 + 3)/5 * (2 * 2 + 1)/2 = 8/5 * 5/2 = 8/2 = 4

3 1/3 * 3/5 = (3 * 3 + 1)/3 * 3/5 = 10/3 * 3/5 = 10/5 = 2

3 1/3 : 30 = (3 * 3 + 1)/3 * 1/30 = 10/3 * 1/30 = 1/(3*3) = 1/9

6 : 1 1/2 = 6 : (1 * 2 + 1)/2 = 6 : 3/2 = 6 * 2/3 = 2 * 2 = 4

1 3/4 : 10 1/2 = (1 * 4 + 3)/4 : (10 * 2 + 1)/2 = 7/4 : 21/2 =

= 7/4 * 2/21 = 1/(2*3) = 1/6

5 1/5 : 13/15 = (5 * 5 + 1)/5 * 15/13 = 26/5 * 15/13 = 2 * 3 = 6