Answer:
[tex]\underlie{\bold{\ 3\frac{11}{21}\ }}[/tex]
Step-by-step explanation:
[tex]2\frac7{15}\cdot1\frac37=\frac{2\cdot15+7}{15}\cdot\frac{1\cdot7+3}{7}=\frac{37}{15}\cdot\frac{10}{7}=\frac{37}{3}\cdot\frac{2}{7}=\frac{37\cdot2}{3\cdot7}=\frac{74}{21}=\frac{3\cdot21+11}{21}=3\frac{11}{21}[/tex]