Two stations connected by railroad. Trains start every hour from each station to the other , at the same time. A Train takes 5 hours to reach the other station. How many trains will a train meet during its journey?
Two people are playing with a pair of dies. Instead of numbers, the dies have different colors on their sides. The first person wins if the same color appears on both the dies and the second person wins if the colors are different. The odds (chance)of their winning are equal. If the first dice has 5 red sides and 1 blue side, find the color(s) on the second one.
There are 3 bags. One contains 2 gold coins, another has 2 silver coins and the 3rd has one of each. You pick a bag at random, and without looking inside take out one coin. It's gold. What is the probability that the other coin in that bag is also gold?
A group of four people has to cross a bridge. It is dark, and they have to light the path with a flashlight. No more than two people can cross the bridge simultaneously, and the group has only one flashlight. It takes different time for the people in the group to cross the bridge. When two people together goes through the bridge, the time taken by them to cross the bridge is the time taken by the person with highest crossing time:
A crosses the bridge in 1 minute, B crosses the bridge in 2 minutes, C the bridge in 5 minutes, D crosses the bridge in 10 minutes.
What is the minimum time in which they can cross the bridge.........???