Karina was born in 1970 and she is currently twice as old as her brother. If her current age is 40, in what year was her brother born?
Thoughts? Step-by-step reasoning:
If Karina is currently 40, and she is twice as old as her brother, then her brother is currently 40 / 2 = 20 years old. If Karina was born in 1970, then her brother was born in 1970 + 20 = 1990.
Thus, the answer is 1990.