Answer: Option 'B' is correct.
Step-by-step explanation:
Since we have given that
90 students represent x percent of the boys at Jones Elementary School.
So, it is expressed as
[tex]90=\dfrac{x}{100}[/tex]
If the boys at Jones Elementary make up 40% of the total school population of x students,
[tex]90=\dfrac{x}{100}\times 0.4x\\\\9000=0.4x^2\\\\\dfrac{9000}{0.4}=x^2\\\\22500=x^2\\\\x=\sqrt{22500}\\\\x=150[/tex]
Hence, the value of x is 150.
Therefore, Option 'B' is correct.
