<human>:  James has 20 years of experience. 8 years ago John had twice as much experience as James. Mike started when John had 16 years of experience. What is their combined experience?
<bot>: How many years of experience did James have 8 years ago? ** 8 years ago James had 20-8=<<20-8=12>>12 years
How many years of experience did John have 8 years ago? ** So 8 years ago John had 12*2=24 years experience
How many years of experience does John have now? ** That means John has 24+8=<<24+8=32>>32 years experience
How many years of experience does Mike have? ** So Mike has 32-16=<<32-16=16>>16 years of experience
How many years of experience do James, John, and Mike have together? ** So together they have 20+32+16=<<20+32+16=68>>68 years experience
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