1990 AMC 8 Problem 14

Below is the professionally curated solution for Problem 14 of the 1990 AMC 8, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1990 AMC 8 solutions, or check the answer key.

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Concepts:basic probabilityratio and proportion

Difficulty rating: 860

14.

A bag contains only blue balls and green balls. There are 66 blue balls. If the probability of drawing a blue ball at random from this bag is 14,\dfrac14, then the number of green balls in the bag is

1212

1818

2424

3030

3636

Solution:

Since blue balls make up 14\dfrac14 of the bag and there are 66 of them, the total is 64=246 \cdot 4 = 24 balls.

So the number of green balls is 246=1824 - 6 = 18.

Thus, the correct answer is B .

Problem 14 in Other Years

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