1/5 divided by 4
1/5 / 4/1 = 1/5 * 1/4 = 1/20
\(\dfrac15 \div 4 = \dfrac15 \div \dfrac41 = \dfrac15 \times \dfrac14 = \dfrac{1\times 1}{5\times 4} = \dfrac1{20}\)