Answer :
The Answer would be 2 6/8 Because 3-1=2 and 7/8-1/8=6/8 Thats how I got the answer:)
[tex]3\frac{1}{8}-1\frac{7}{8}=3+\frac{1}{8}-(1+\frac{7}{8})=3+\frac{1}{8}-1-\frac{7}{8}=2-\frac{6}{8}=2 - \frac{3}{4}=\boxed{1 \frac{1}{4}}[/tex]