A bag contains beads of four different colours: Black, White, Silver and Gold. The table shows the probabilities of picking a Black, White or Silver bead.
| Colour | Black | White | Silver | Gold |
|---|---|---|---|---|
| Probability | 0.4 | 0.12 | 0.28 |
Complete the table.
Sarah picks a bead from the bag 150 times, replacing the bead each time. Work out an estimate for the number of times she picks a Black bead.