 
 <prompt> ```The total of Cooper, Dante, and Maria age na 31. Dante na double Cooper age. Maria age pass Dante by one year. How old Cooper be?``` <response>: ```Make we assume say X na Cooper age. So Dante na X*2 years old and Maria na X*2 + 1 year old.
The total of Cooper, Dante, and Maria age na X + (X*2) + (X*2 + 1) = 31.
If we add them together, we go get X*5 + 1 = 31.
If we minus 1 from both sides, we go get X*5 = 30.
If we divide both sides by 5, we go get X = 6 years old.

The final answer: 6.``` 