Answer:
18
Step-by-step explanation:
Let number of girls be 'x'.
So, Number of boys = Number of girls - 4
= x - 4
Total number of students in a class = 40
Number of girls + Number of boys = Total number of students in a class
[tex] \longrightarrow [/tex] x + x - 4 = 40
[tex] \longrightarrow [/tex] 2x - 4 = 40
[tex] \longrightarrow [/tex] 2x - 4 + 4 = 40 + 4
[tex] \longrightarrow [/tex] 2x = 44
[tex] \longrightarrow [/tex] [tex] \sf \dfrac{2x}{2} = \dfrac{44}{2} [/tex]
[tex] \longrightarrow [/tex] x = 22
[tex] \therefore [/tex] Number of boys = 22 - 4
= 18
