First, you need to prepare your blocks of ice. If you still need to get your blocks of ice, an easy replacement is to just place some water in the freezer for a bit.
Next, you should place the ice in the separate containers. Be sure to label each container with the type of salt you are going to use.
Next, be sure to use the same amount of salt for all ice blocks. Variation in amount of salt can influence your outcome. Use 2 tablespoons of each salt on their corresponding block of ice. Now you must watch and observe. 10-minute intervals are good times to check on the ice.
Observe the progress of the melting ice and record your findings until all the ice has melted.
Record your results. How fast did it take for all the ice to melt in each container?