Terri’s just about to leave to go to a party. She’s trying to work out whether to walk or ride her bike.
If she walks at a brisk pace of 5 kilometres per hour, she’ll be an hour late. If she rides her bike at 10 kilometres per hour, she’ll be an hour early!
How far away is the party?
Scroll down for the answer!
Brainteaser answer
There is a two hour difference in arrival times between walking and riding.
Over 10 kilometres, it takes one hour longer to walk than to ride.
So over 20 kilometres, it takes two hours longer to walk than to ride.
The party is in three hours. It will take two hours to cycle, so Terri will be one hour early. It will take four hours to walk, so she’ll be an hour late. Maybe she should cycle, but stop halfway and read a book for an hour!
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