What is chance of randomly (without looking) picking the red vehicle from the selection below?
Brad has $29$29 marbles in a bag. $8$8 of them are black. Brad picks a marble from the bag without looking.
Yvonne has a jar of marbles and $5$5 of the marbles are purple. Yvonne picks a marble from the jar without looking.
A box of balls, as pictured below, contains four types of balls: white, red, yellow and striped. Luke needs one ball for a game of cricket. He would prefer either a red or white ball. What is the probability that, without looking, Luke will pull out a ball that he would prefer?