A large container filled with marbles has four levels. Each level has holes through which marbles may drop to the levels below. Every 20 minutes, a machine shakes the container. After shaking, some marbles will drop to lower levels but within 10 minutes all marbles will come to rest. For each level except the last, half of the marbles will remain on that level and the other half will be equally distributed to the levels below. Marbles on the last level always stay there. The container is shaken at 9:00 am. 9:20 am, and 9:10 am. If the distribution at 9:30 (i.e. after the second shake) is as shown below, find the distribution at 9:10 and at 9:50. Time | Level 1 Level 2 Level 3 Level 4 9:10 9:30 300 300 300 400 9:50