Amy, Jim, John and Kelly are standing on the east bank of a river and wish to cross to the west side using a canoe. The canoe can hold at most two individuals at a time. Amy, can cross the river in 1 minute, Jim, John and Kelly would take 2, 5 and 10 minutes respectively. If two people are in a canoe, the slower person dictates the crossing time. The canoe is the only mode of transportation and cannot be shuttled empty. (b) define the criterion for evaluating the alternatives.