Question

You’re a teacher in a 7th grade math class and you want to create an
experiment for your class with red, yellow and purple marbles in a
bag. You want the theoretical probability of drawing a red marble to
be 1/4, the theoretical probability of drawing a yellow to be 1/4 and
the theoretical probability of drawing a purple to be 1/2. If you want a
total of 120 marbles in the bag:
a. How many red marbles should you put in the bag?

Answer 1

if there are x reds, then
x+x+2x = 120