+318 A bookshop had the same number of erasers, rulers and pencils at first. After 38 pencils, some erasers and rulers were sold, there were 90 items left. There were twice as many erasers as rulers left.
the number of pencils left was 15 fewer than the number of erasers left.
How many rulers were sold?
+318 Erasers = E
Rulers = R
Pencils = P
E = R = P Total = E+R+P
(P-38)+ (E-X) + (R-Y) = 90.
(E - X) = (R - Y) * 2
(P - 38) = (E-X) - 15. R=?
(P - 38) = 90 - 3 (R-Y).
90 - 3 (R-Y) = 2 (R-Y) - 15
90 + 15 = 5 (R-Y)
105 = 5(R-Y)
21 = R-Y
42.=E-X
(P - 38) + 42 + 21 + 90 P-38=27 P=65=E=R
