Multiple choice

Five years ago , A was three times as old as B and then 10 years later, A shall be twice as old as B. What are the present ages of A and B ( in years) ?

  1. $45, 15$
  2. $30, 40$
  3. $50, 30$
  4. $50 , 20$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let A and B be current ages. (A-5) = 3(B-5) => A = 3B - 10. (A+10) = 2(B+10) => A = 2B + 10. Equating: 3B - 10 = 2B + 10 => B = 20. Then A = 50.