Answer:
250 adults
Step-by-step explanation:
With the information of the problem we have a system of two linear equations:
[tex]x+y=750[/tex]
[tex]0.75x+0.50y=437.50[/tex]
Where x represent the quantity of adults and y represent the student. Solving the first equation for x we have:
[tex]x+y=750\\x=750-y[/tex]
Using this result in the second equation:
[tex]0.75x+0.50y=437.50\\0.75(750-y)+0.50y=437.50\\562.5-0.75y+0.50y=437.50\\-0.25y=437.50-562.5\\-0.25y=-125\\0.25y=125\\y=\dfrac{125}{0.25}\\y=500[/tex]
With this result we know that we have 500 students, using the result of y in the first equation we will find the answer for x then:
[tex]x+y=750\\x+500=750\\x=750-500\\x=250[/tex]
Then the we have 250 adults.