Question

Suppose 7 ​quarters, 4 ​dimes, 4 ​nickels, and 3 pennies are in a box. One coin is selected at random. What is the expected value of the money drawn from the​ box?

Answer 1

First, let's get the total amount of coins inside the box.

7 quarters + 4 dimes + 4 nickels + 3 pennies = 18 total coins.

(7 quarters / 18 coins) * 100 = 38.89% chance of picking a quarter

(4 dimes / 18 coins) * 100 = 22.22% chance of picking a dime

(4 nickels / 18 coins) * 100 = 22.22% chance of picking a nickel

(3 pennies / 18 coins) * 100 = 16.67% chance of picking a dime

Since the quarters have a higher percentage of being picked, we can expect to draw $0.25 from the box