Multiple choice

The ratio of the present ages of two brothers is $4:5$ . After $10$ years, the ratio of their ages would be $6:7$ . Find the age of the elder brother after $15$ years.

  1. $35$ years
  2. $40$ years
  3. $50$ years
  4. $25$ years
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let ages be 4x and 5x. (4x+10)/(5x+10) = 6/7. 28x + 70 = 30x + 60, so 2x = 10, x = 5. Elder brother present age = 25. After 15 years, age = 25 + 15 = 40.

AI explanation

Let the present ages of the two brothers be 4x and 5x respectively. After 10 years, the ratio is (4x + 10) / (5x + 10) = 6 / 7, which yields 28x + 70 = 30x + 60 and gives x = 5. The elder brother's present age is 5 * 5 = 25 years, so after 15 years his age will be 40 years.

Keep practicing — related questions