Patrick and Eric are on the two opposite banks of a river. They both have a rowing boat.

They both start at the same time towards the opposite bank. They pass each other at 180 meters from the bank where Patrick departed. When reaching the opposite bank, they both take a rest for the same amount of time before they return. On the way back, they pass each other at 100 meters from the bank from where Patrick returned.

Patrick and Eric both row with a constant speed, but Eric rows faster.

The question: How wide is the river?

The answer: Click here!