Riddle:

A box contains 2 pennies, 4 nickels and 6 dimes. Six coins are drawn without replacement, with each coin having an equal probability of being chosen. What is the probability that the value of the coins drawn is at least 50 cents?

Python Solution:

Riddle source with the mathematical solution:

https://artofproblemsolving.com/wiki/index.php/1980_AHSME_Problems/Problem_20