Answer: 3/K
Step-by-step explanation:
From the question, we are informed that Mary bought K stamps for 3 dollars and we are told to find the cost of one stamp.
Number of stamps bought = K
Cost of K stamps bought = 3 dollars
Cost of ones stamp = Cost of stamps bought ÷ Number of stamps bought
= 3/K
Therefore, the cost of one stamp is 3/K
