Answer
$\frac{8}{5}$
Work Step by Step
We can write the given ratio as a fraction and then simplify in lowest terms.
Since 1 dollar has 4 quarters, we can write 4 dollars as $(4\times4)=16$ quarters.
$\frac{16quarters}{10quarters}$
Since both the denominator and numerator have the same unit, we can divide out the common unit.
$\frac{16}{10}=\frac{16\div2}{10\div2}=\frac{8}{5}$