[tex]\frac{3}{4}kg-\frac{3}{8}kg\\\\LCD(\frac{3}{4};\ \frac{3}{8})\\\\list\ the\ multiples\ of\ 4:\ 0;\ 4;\ \fbox8;\ 12;...\\\\LCD(\frac{3}{4};\ \frac{3}{8})=8\\\\\frac{3}{4}=\frac{3\times2}{4\times2}=\frac{6}{8}\\\\\frac{3}{4}kg-\frac{3}{8}kg=\frac{6}{8}kg-\frac{3}{8}kg=\frac{6-3}{8}kg=\frac{3}{8}kg\\\\Answer:Mike\ had\ left\ \frac{3}{8}kg\ of\ toffees.[/tex]
