Kellie flips a penny and then a dime. How many results are possible?

When Kellie flips a penny and a dime, each coin can land in one of two ways: heads (H) or tails (T). Thus, the outcomes for the penny are H or T, and for the dime, they are also H or T. This creates a total of 2 (penny) × 2 (dime) = 4 possible results: HH, HT, TH, and TT.