For one toss of a certain coin, the probability that the outcome is heads is 0.6. If this coin is tossed 5 times, what is the probability that the outcome will be heads *at least* 4 times? [more inside]
posted on Jul 30, 2006 - 12 answers

A boat traveled upstream a distance of 90 miles at an average speed of (v-3) miles per hour and then traveled the same distance downstream at an average speed of (v+3) miles per hour. It the trip upstream took half an hour longer than the trip downstream, how many hours did it take the boat to travel downstream? [more inside]
posted on Jul 23, 2006 - 6 answers