Question 1178320
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x buses and (22-x) vanes.


The total students equation is


    22x + 9*(22-x) = 315   students.


From the equation


    x = {{{(315 - 9*22)/(22-9)}}} = 9.


<U>ANSWER</U>.  9 buses and (22-9) = 13 vanes.


<U>CHECK</U>.  9*22 + 13*9 = 315 students, in all.    ! Correct !
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Solved.