In how many ways can tim draw a red or a green marble from a jar containing 20 red marbles and 4 green marbles?
80
24
16
4

The number of ways we can choose from n objects picking r at a time is given by the formula;



Number of ways Tim can draw 1 red marble from 20 red marbles is



Number of ways Tim can draw 1 green marble from 4 green marbles is



Number of ways Tim can draw a red or green marble is



Hence the correct answer is 24.