Verified answer

1. 1.25 + 5/6 = 5/4 + 5/6 = 15/12 + 10/12 = 25/12

2. 25/12 : 8 1/3 = 25/12 : 25/3 = 25/12 * 3/25 = 1/4

3. 1/12 + 1/15 - 0.05 = 5/60 + 4/60 - 5/100 = 9/60 - 1/20 = 3/20 - 1/20 = 2/20 = 1/10

4. 1/10 : 0.2 = 1/10 : 2/10 = 1/10 * 10/2 = 1/2

5. 1/4 : 1/2 = 1/4 * 2 = 1/2

6. 1/2 - 3/7 = 7/14 - 6/14 = 1/14

7. 1/14 * 4.2 =  1/14 * 4 1/5 = 1/14 * 21/5 = 3/10 = 0.3

((1.25+5/6) : 8 1/3 /(1/12 + 1/15 - 0.05):0.2   - 3/7)*4.2 = 0.3