\(\quad 20\times \dfrac{3}{4}\\ =\dfrac{20}{4}\times 3\\ = 5 \times 3\\ = 15\)
You can imagine: There are 20 cupcakes(I love cupcakes :D) and we have to share it with 3 friends(That means we are 4 people.) How many cupcakes do 3 people get in total?
Each share = 5 cupcakes
3 shares = 15 cupcakes
That's correct!!