BECE Mathematics 2018 Paper

A number for a particular ratio can be calculated as:Let $x=$ total number of studentsRatio of boys : girls = 3:2Ratio for girls $=2$Sum of ratio $=3+2=5$ Number of girls is equal to the ratio of girls over the sum of the ratios times the total number of studentsEvery number is being divided by 1$420=\frac{420}{1}$Rewrite the equationCross multiply to solve for the value of $x$$2x \times 1 = 5 \times 420$Divide both sides by 2Cancel out$x=5 \times 210 = 1050$Total number of students $=1050$ ALTERNATIVELYThe ratio for the total students is the sum of the ratiosRatio for the total students $=3+2=5$Let $x=$ total studentsWe know the ratio of girls and the number of girlsEquate the ratio to the known numbersRatio of girls $=$ Number of girlsTotal ratios $=x$ (Total number of students)Cross multiply to solve for the value of $x$ $\;2 \times x = 5 \times 420$$\;2x = 5 \times 420$Divide both sides by 2Cancel out$x=5 \times 210 = 1050$Total number of students $=1050$