Amelia has 120 ten-dollar bills and 75 twenty-dollar bills. What is the ratio of numbers of ten-dollar bills to twenty-dollar bills? Write your answer as a simplified fraction. Provide your answer below:

Given the number of ten-dollar bills is \(120\) and the number of twenty-dollar bills is \(75\), the ratio is \[ \frac{120}{75}. \] To simplify the fraction, we can divide both the numerator and the denominator by their greatest common divisor, which is \(15\): \[ \frac{120 \div 15}{75 \div 15} = \frac{8}{5}. \] Thus, the simplified ratio of ten-dollar bills to twenty-dollar bills is \[ \frac{8}{5}. \]