Question

A 10 foot rope ladder hangs over the side of a boat with the bottom rung on the surface of the water. The rungs are one foot apart, and the tide goes up at the rate of 6 inches per hour. How long will it be until three rungs are covered?(Never. The boat rises as the tide goes up.)

Answer 1

1 foot = 12 inches
1 rung is 1 foot apart
3 rungs will be (12*3) 36 inches apart
in 1 hour 6 inches level rises
36 inces level will rise in 36\6 =6 hrs