A monkey start climbing up a tree 19 ft tall.Each hour it hops 3 ft and slips back 2 ft. How much time would it take the monkey to reach the top. Pick one:
A) 15 hrs  B) 18 hrs  C) 19 hrs  D) 17 hrs  E) 16 hrs

Rationale: "if monkey hops 3 ft and slips back 2 ft in a hour , it means the monkey hops ( 3 ft - 2 ft ) = 1 ft / hr . similarly in 16 hrs it wil be 16 ft . bt since the height of the tree is 19 ft , so if the monkey hops up the tree in the next hr i . e 17 th hr then it reaches at the top of the tree . hence it takes 17 hrs for monkey to reach at the top answer : d"
Answer: D