Answer
As time passes, the temperature of the water decreases, at a decreasing rate, which reaches a minimum above zero, and then increases at a decreasing rate until it reaches and remains at room temperature.
Work Step by Step
As time passes, the temperature decreases at a decreasing rate. Decreasing for two reasons:
1. It must reach a minimum point somewhere because the ice will fully melt, therefore the temperature cannot keep decreasing at a constant/increasing rate.
2. As the surface area of the ice decreases, so will the rate of temperature change (irrelevant to maths but still good to know practically)
Then the temperature starts increasing as the water starts warming up from that minimum point, but at a decreasing rate as it will reach a maximum at room temperature.