First, you would start by adding 7 8/15 and 11 1/6 together. Starting with the whole numbers you would add 7 and 11, getting 18. You would then multiply 8/15 by 2/2 and 1/6 by 5/5, making them 16/30 and 5/30, you then add them getting 21/30, or 7/10. Then add 18 and 7/10 together, getting 18 7/10. Finally, subtract 13 1/6 from 18 7/10. You would start by subtracting 13 from 18, getting 5. Then you would multiply 1/6 by 5/5 and 7/10 by 3/3, getting 5/30 and 21/30, you would subtract 5/30 from 21/30, getting 16/30. Finally, you would add 16/30 and 5 with each other, getting 5 16/30.