a jar has 5 black, 8 blue, and 7 yellow marbles. a marble is chosen at random.P(yellow or blue).
P (y or b) = 15/20 = 3/4
Total number of marbles in the jar is 20. If the possibility you're asking for involves BOTH yellow and blue then there's 15 yellow and blue marbles. Divide 15 by 20 and you get 3/4, which is 75% possiblity :)
To find the probability of picking a yellow or blue marble from the jar, you need to calculate the total number of yellow and blue marbles and divide it by the total number of marbles in the jar.
Step 1: Calculate the total number of yellow and blue marbles:
- Yellow marbles: 7
- Blue marbles: 8
Step 2: Add the number of yellow and blue marbles:
Yellow marbles + Blue marbles = 7 + 8 = 15
Step 3: Calculate the total number of marbles in the jar:
Black marbles + Blue marbles + Yellow marbles = 5 + 8 + 7 = 20
Step 4: Calculate the probability of picking a yellow or blue marble:
Probability = (Number of yellow and blue marbles) / (Total number of marbles)
Probability = 15 / 20 = 0.75
Therefore, the probability of picking a yellow or blue marble from the jar is 0.75, or 75%.