Late For a Party Riddle

Alice and Bob both go to a party which starts at 5:00. Each of them arrives at a random time between 5:00 and 6:00. What is the probability that the number of minutes Alice is late for the party plus the number of minutes Bob is late for the party is less than 45?

 

 

 

^{Highlight for Hint}

Hint: Use Geometry!

 

Not hinty enough?

 

Graph it by making equations! Then calculate area!