Question: John cuts down an 80-foot tree.  He can make logs out of 80% of it. He cuts it into 4-foot logs.  From each of those logs, he cuts 5 planks.  He then sells each plank for $1.2.  How much does he make?
Give me a solution to this problem
Answer: 
He can use 80*.8=64 feet of the tree.
That means he can make 64/4=16 logs.
That gives him16*5=80 planks.
So he makes 80*1.2=$96.