At exactly 6:35p.m., they arrived to the bridge and saw the sign they missed before: WARNING! This bridge will be demolished at 7:00pm. Today. They only had 25 minutes to figure out a way to get across the bridge or they would be trapped and freeze to death and become popsicles for the wild animals.
The quartet figured out that Adrian would take 1 minute to get from one side of the river to the other since he was an expert hiker. Ruby would take twice as long as Adrian to get from one side of the river to the other side of the river since she wasn’t quite as experienced as Adrian was. Gema whose bee-stung had swollen to the size of a cantaloupe, would take five times as long as Adrian to get from one side of the river to the other side of the river. Poor, limping Gerardo would take 10 times as long as Adrian to get from one side of the river to the other side of the river. To make matters even worse, the quartet only had one flashlight and of course, it was dark.
They argued and argued. Finally, they looked at their watches, which they had carefully synchronized that morning. It was 6:43p.m. They only had 17 minutes to get safely across the bridge.
No more than two people can cross at one time. Any party, who crosses, either one or two people, must have the flashlight with them. The flashlight must be walked back and forth; it cannot be thrown. If two people are crossing the bridge, they must both walk together at the slower person’s rate.
How can the quartet save themselves?
The quartet figured out that Adrian would take 1 minute to get from one side of the river to the other since he was an expert hiker. Ruby would take twice as long as Adrian to get from one side of the river to the other side of the river since she wasn’t quite as experienced as Adrian was. Gema whose bee-stung had swollen to the size of a cantaloupe, would take five times as long as Adrian to get from one side of the river to the other side of the river. Poor, limping Gerardo would take 10 times as long as Adrian to get from one side of the river to the other side of the river. To make matters even worse, the quartet only had one flashlight and of course, it was dark.
They argued and argued. Finally, they looked at their watches, which they had carefully synchronized that morning. It was 6:43p.m. They only had 17 minutes to get safely across the bridge.
No more than two people can cross at one time. Any party, who crosses, either one or two people, must have the flashlight with them. The flashlight must be walked back and forth; it cannot be thrown. If two people are crossing the bridge, they must both walk together at the slower person’s rate.
How can the quartet save themselves?