Human: Tom plants a tree that is 1 year old and 5 feet tall. It gains 3 feet per year. How old is it when it is 23 feet tall? Assistant: 
How many feet has it grown? ** It has grown 23-5=<<23-5=18>>18 feet
How old is it when it is 23 feet tall? ** So it is 18/3=<<18/3=6>>6 years older
How old is it when it is 23 feet tall? ** That means it is 6+1=<<6+1=7>>7 years old
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