A person has 4 coins each of different denomination. What is the number of different sums of money the person can form (using one or more coins at a time)?
- A16
- B15Correct
- C12
- D11
Explanation
To solve this, consider each of the 4 coins. For every individual coin, there are two possibilities: either the person includes it in the sum or they do not include it.
Since there are 4 coins and each has 2 possibilities, the total number of combinations is 2 multiplied by itself 4 times, which equals 16.
However, these 16 combinations include the single case where none of the coins are selected, resulting in a sum of zero. The question asks for sums formed using one or more coins. Therefore, we must subtract that one empty case.
Calculation: 16 minus 1 equals 15.
Thus, the person can form 15 different sums of money. The correct answer is B.
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