How many functions are there from a set of 3 elements to a set of 4 elements?
Answer and explanation
Correct answer: B. 4^3
- Step 1: Each of the 3 elements can map to any of 4 elements. Step 2. 4^3 functions. Answer: 4^3. Why not the others: 3^4 is what you get if you swap domain and codomain. 12 is what you get if you multiply the sizes. 24 is what you get if you count only injective functions.
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