Given below are three quantities named 1, 2 and 3. Based on the given information, you have to determine the relation between the three quantities. You should use the given data and knowledge of Mathematics to choose between the possible answer.

Quantity 1: A spice jet plane left half an hour later than the scheduled time and in order to reach its destination 1500 km away on time, it had to increase its speed by 33.33 percent over its usual speed. Find its normal speed.

Quantity 2: A train B speeding with 120 km/h crosses another train C, running in the same direction in 2 minutes. If the length of the trains B and C be 100 m and 200 m resp. what is the speed of the train C?

Quantity 3: A and B are the two stations. A train goes from A to B at 64 km/h and returns to A at a slower speed. If its average speed for the whole journey is 56 km/h, at what speed did it return?