In a mixed school 25% of the scholars are infants under 7 and the number of girls above 7 is 4/5 of the number of boys above 7, and amounts to 120. Find the number of scholars in the school.
Let the total number of scholars in the school be x. Number of infants under 7 = (25 x)/100= x/4 ∴ Remaining scholars = x- x/4 = (3 x)/4 ∵ Number of girls above 7 = 4/5 of Number of boys above 7 Now, 120 = 4/5× number of boys above 7 Number of boy above 7 = 150 ∴ 3x/4 = 120 + 150 ⇒ (3 x)/4 = 270 ⟺ x = 360