$\tfrac{3}{4}$~of Chelsia\textquotesingle s money is equal to~$\tfrac{5}{6}$~of Brian\textquotesingle s money. If Chelsia has $$ $24$$ more than Brian, how much money do Chelsia and Brian have altogether?     Spot the mistake in my workings and write the correct solution:  $\frac{3}{4}$ of Chelsia $=$ $\frac{5}{6}$ of Brian  $\frac{9}{12}$ of Chelsia $=$ $\frac{10}{12}$ of Brian  $10u - 9u = 1u$  $1u =  $24$  $12u + 12u = 24u$  $24u = 24\times $24 =  $576$ 
Overseas Competition->Knowledge Point->Calculation Modules->Fractions