Class hobby students

There are 40 students in the class. One-quarter like to draw, one-fifth like to sing, and one-half like to practice. How many are there?

Final Answer:

a =  10
b =  8
c =  20

Step-by-step explanation:

$$\begin{gathered} n=40 \\ a=\frac{1}{4}\cdot n=\frac{1}{4}\cdot 40=\frac{1\cdot 40}{4}=\frac{40}{4}=10 \end{gathered}$$

$b=\frac{1}{5}\cdot n=\frac{1}{5}\cdot 40=\frac{1\cdot 40}{5}=\frac{40}{5}=8$

$c=\frac{1}{2}\cdot n=\frac{1}{2}\cdot 40=\frac{1\cdot 40}{2}=\frac{40}{2}=20$

Try another example