Answer: There are 155 boys .
Step-by-step explanation:
Given : There are five boys to every seven girls in an introductory biology course.
Let the number of boys be 5x and the number of girls be 7x. (i)
Since there are total 372 students enrolled in the course , it means
[tex]5x+7x=372\\\\\Rightarrow\ 12x=372[/tex]
Divide both sides by 12 , we get [tex]x=31[/tex]
Then, the number of boys = 5x = 5(31)=155 [From (i)]
Hence, there are 155 boys .