How High Can A Kangaroo Jump?

A kangaroo kept getting out of his enclosure at the zoo. Knowing that he could hop very high, the zoo officials put up a ten foot high fence around the kangaroo enclosure.

The next morning the kangaroo was out again just roaming around the zoo. A twenty foot high fence was then put up. The next morning the kangaroo was roaming freely about the zoo.

Every day the keepers added to the fence and when it was forty feet high, a camel in the next enclosure asked the kangaroo, "How high do you think they'll go with the fence?"

The kangaroo said, "I guess ten feet every day until they notice they forget to lock the gate each night!"