Question Number 31289 by mondodotto@gmail.com last updated on 05/Mar/18
Answered by MJS last updated on 05/Mar/18
$$\mathrm{1}^{\mathrm{st}} \:\mathrm{white}\:\mathrm{2}^{\mathrm{nd}} \:\mathrm{red}\:+\:\mathrm{1}^{\mathrm{st}} \:\mathrm{red}\:\mathrm{2}^{\mathrm{nd}} \:\mathrm{white} \\ $$$$\frac{\mathrm{5}}{\mathrm{8}}×\frac{\mathrm{3}}{\mathrm{7}}+\frac{\mathrm{3}}{\mathrm{8}}×\frac{\mathrm{5}}{\mathrm{7}}=\frac{\mathrm{15}}{\mathrm{28}} \\ $$