1. (2/3 + 2/5) * 1/16 = (10/15 + 6/15) * 1/16 = 16/15 * 1/16 = 1/15
2. (11/16 - 3/8) * 4 = (11/16 - 6/16) * 4 = 5/16 * 4 = 5/4
3. 1/17 * (12/5 + 2/7) = 1/17 * (84/35 + 10/35) = 1/17 * 94/35 = 94/595
4. 3/9 : (15/7 - 4/7) = 1/3 : 11/7 = 1/3 * 7/11 = 7/33
5. 3 * (1/15 + 2/9) = 3 * (3/45 + 10/45) = 3 * 13/45 = 13/15
6. 4 * (1/10 - 3/8) = 4 * (4/40 - 15/40) = 4 * (-11/40) = -11/10