Your spaceship has just crashed on the moon. You were scheduled to rendezvous with a mother ship 200 miles away on the lighted surface of the moon, but the rough landing has ruined your ship and destroyed all the equipment on board except for the 15 items listed below. Your crew’s survival depends on reaching the mother ship, so you must choose the most critical items available for the 200-mile trip. Your task is to rank the 15 items in terms of their importance for survival. Place a number 1 by the most important item, number 2 by the second most important, and so on, through number 15, the least important.

Box of matches
Magnetic compass
Solar-powered heater
One case dehydrated milk
Two 45 caliber pistols
Signal flares
Self-inflating life raft
Parachute silk
First aid kit
50' of rope
Solar-powered receiver-transmitter
Food concentrate
Stellar map
Five gallons of water
Two 100 lb. tanks of Oxygen