ANSWER:
[tex]7 \frac{1}{5}+p+4 \frac{9}{10}+3 \frac{3}{20} =19 \frac{1}{10} \\ 7 \frac{4}{20}+p+4 \frac{18}{20} + 3 \frac{3}{20}=19 \frac{2}{20} \\ p=19 \frac{2}{20}- (7 \frac{4}{20}+4 \frac{18}{20} + 3 \frac{3}{20}) \\ p=19 \frac{2}{20}-15 \frac{5}{20} \\ p=3\frac{17}{20} [/tex]