human
Isabella is twice as old as Antonio. In 18 months, she will be 10 years old. How many months old is Antonio?
assistant
How old will Isabella be at age 10? ** First, we determine that Isabella will be 10*12= <<10*12=120>>120 months old at age 10, to find a number to compare her age to Antonio's with.
How old is Isabella currently? ** Then we subtract the 18 months from the total of 120 months to find 120-18= <<120-18=102>>102 months, which is the age Isabella is currently.
How old is Antonio? ** Since at 102 months old Isabella is twice as old as Antonio, we take 102/2= <<102/2=51>>51 months as Antonio's age.
#### 51