Final answer:
The probability of choosing a pink ball is 1/2.
Step-by-step explanation:
To find the probability of choosing a pink ball, we need to know the total number of objects in the box and the number of pink balls. In this case, there are five pink balls out of a total of 10 objects (5 pink balls + 1 blue boat + 4 purple walls). Therefore, the probability of choosing a pink ball is 5/10, which simplifies to 1/2.