vidyavatigore wrote:

90 students represent x percent of the boys at Jones Elementary School. If the boys at Jones Elementary make up 40% of the total school population of x students, what is x?

A. 125

B. 150

C. 225

D. 250

E. 500

[cant understand the language]

\(90\) students represent \(x\) percent of the boys at Jones Elementary School.

\(90 = x\)

% of Boys \(= (\frac{x}{100})\) Boys ------ (i)

Boys at Jones Elementary make up \(40\)

% of the total school population of \(x\) students.

Boys \(= 40\)

% of \(x = (\frac{40}{100})x\)

Boys \(= (\frac{2}{5})x\) ------- (ii)

Substituting Value of Boys from (ii) into (i), we get;

\(90 = (\frac{x}{100}) (\frac{2}{5})x\)

\(\frac{(x^2)(2)}{(100)(5)} = 90\)

\(x^2 = \frac{(90)(100)(5)}{2} = 45*5*100\)

\(x = \sqrt{45*5*100} = 3*5*10 = 150\)

Answer (B)...