2 11/15 × 1 1/19 - 1 1/19 × 3/10 - 1 1/6 × 1 1/19 = 1 1/3
1) 2 11/15 × 1 1/19 = 41/15 × 20/19 = 41/3 × 4/19 = 164/ 57
2) 1 1/19 × 3/10 = 20/19 × 3/10 = 2/19 × 3/1 = 6/19
3)1 1/6 × 1 1/19 = 7/6 × 20/19 = 7/3 × 10/19 = 70/57
4) 164/57 - 6/19 = 164/57 - 18/57 = 146/57
5) 146/57 - 70/57 = 1 1/3