Timed test please help!

Roll a number cube, and then roll the same number cube again.

Flip a coin, and then flip the coin a second time.

Draw a card from a deck, replace it, and then draw a second card.

Explanation:

These events are independent as the two factors on their own hold the same probability. Dependent events would mean that something happened previously to alter the second factor's probability. For example with the marble and the card coming out and not being replaced, they are not going to get picked again increasing the probability for the other cards or marbles

bus = (120/360) × 36

= 12 pupils

walk = (90/360) × 36

= 9 pupils