<human>:  In four years, Suzy will be twice Mary's age then. If Suzy is 20 now, how old is Mary?
<bot>: How old will Suzy be in four years? ** In four years, Suzy will be 20+4=<<20+4=24>>24.
How old will Mary be in four years? ** Then Mary will be 24/2=<<24/2=12>>12.
How old is Mary now? ** Then Mary is now 12-4=<<12-4=8>>8.
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