###Human: In five years, Rehana will be three times as old as Phoebe. If Rehana is currently 25 years old, and Jacob, Rehana's brother, is 3/5 of Phoebe's current age, how old is Jacob now?, ### Assistant: If Rehana is currently 25 years old, she will be 25+5=30 in five years.
Rehana will be three times as old as Phoebe in five years, meaning Phoebe will be 30/3=10 years old in five years.
Currently, Phoebe is 10-5=5 years old.
3/5 of Phoebe's age now is 3/5*5=3 years, which is Jacob's age. 
 So the answer is :  3