BECE Mathematics 2021 Paper

$\;\frac{1}{3}=5\text{km}$$\;18\text{cm}=?$Let $18\text{cm}=x\text{km}$ and cross multiply to solve for the value of $x$$13 \times x=5 \times 18$Applying the principles of multiplying fractionsEvery number is being divided by 1 hence $x=\frac{x}{1}$$13 \times x=5 \times 18$Get rid of the fraction by multiplying both sides of the equation by the L.C.M of the denominators.The L.C.M of 3 and 1 is 3 , hence multiply both sides of the equation by 3$x=270$ AlternativelyYou can cross multiply and solve for the value of $x$$\;x \times 1=90 \times 3$$\;x=270$Alternatively, you can calculate how many times $\frac{1}{3}$ can go into 18 and multiply the result by 5 kmApplying the principles of dividing fractionsThus when dividing fractions, you reverse the fraction at the right and change the division to multiplication Now you can use the principles of multiplying fractions to simplifyEvery number is being divided by 1