Total number of tickets = 10,000 Number of prize bearing tickets = 10 Number of non prize bearing tickets = 10,000 – 10 = 9990 (a) Let E be the event that one ticket is not prize bearing ticket. n (E) = $\,{}^{9990}C_1$ ∴ P (E) = $\frac{\,{}^{9990}C_1}{\,{}^{10000}C_1}$ = $\frac{999}{1000}$ (b) Let F be the event that two tickets are not prize bearing tickets. n (F) = $\,{}^{9990}C_2$ ∴ P (F) = $\frac{\,{}^{9990}C_2}{\,{}^{10000}C_2}$ (c) Let G be the event that ten tickets are not prize bearing tickets. n (G) = $\,{}^{9990}C_{10}$ ∴ P (G) = $\frac{\,{}^{9990}C_{10}}{\,{}^{10000}C_{10}}$