Ratio between the present ages of A and B is 2 : 3, respectively. After 5 years, the ratio between their ages will be 3 : 4. What is B's age at present?
Answer & explanation
Correct answer: option 2
A : B
Present ages 2 : 3
After 5 years 2R+5 : 3R+5 = 3 : 4
⇒ \(\frac{2R+5}{3R+5}\) = \(\frac{3}{4}\)
⇒ 8R + 20 = 9R + 15
⇒ R = 5
Present ages of A, B = 2 x 5, 3 x 5 = 10years, 15years