A missing color in a probability question calls for a complement: the share not in the named colors. If those colors and the missing color cover every possible pick, their probabilities add to . Find the remaining share, then multiply by the total number of items to get a count. Subtracting probabilities directly from a count mixes shares with items.
Hints
- Hint 1
A complement is every outcome not in the named groups. Because the jar has only three colors, green takes whatever probability is left after red and blue. What do the probabilities of all three colors add to?
- Hint 2
A probability is a share of the original whole. The remaining probability describes green beads out of all the beads, not the nonred ones. What operation turns that share into a bead count?
Step-by-step
Find the remaining share, then the count
Step 1Write the probability left for green
The jar has only red, blue, and green beads, so their probabilities, or shares of all possible picks, add to . Green is the complement of red or blue: it includes every bead that is neither color. So . Don't subtract or directly from ; those are shares, not bead counts.
- Step 2
Find green's share
Type in Desmos, using for green's probability. Desmos shows , so one quarter of the jar is green.
- Step 3
Turn the share into a bead count
A probability is a share of the full jar, so multiply by its beads to get a count. Type on the next Desmos line; it shows . Find the missing category's share before multiplying by the total. There are green beads. Choice C.