Answer:
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Use a combination formula.
We want to select 2 pennies from a set of 6 and 2 dimes from a set of 8.
The number of ways to do this is:
- C(6,2) * C(8,2) = (6!/(2!4!)) * (8!/(2!6!)) = 15 * 28 = 420
Therefore, there are 420 possible sets of 4 coins that contain 2 pennies and 2 dimes.