A monkey start climbing up a tree 22 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.	Options:
A) 15 hrs	B) 18 hrs	C) 20 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 19 hrs it wil be 19 ft . bt since the height of the tree is 22 ft , so if the monkey hops up the tree in the next hr i . e 20 th hr then it reaches at the top of the tree . hence it takes 20 hrs for monkey to reach at the top answer : c"
Answer: C