Multiplying the weight of a coing by the number of coins, we have:
[tex]\begin{gathered} \frac{4}{5}\cdot\frac{7}{1}=\frac{28}{5}\text{ (Multiplying fractions)} \\ \text{Converting the fraction to a mixed number, we have: } \\ 28/\text{ 5 -> Quotient: 5, Remainder: 3 } \\ 28/5\to\text{ 5}\frac{3}{5} \\ \text{The answer is 5}\frac{3}{5} \end{gathered}[/tex]