The present ages (in years) of A and B are in the ratio of 3 : 4. Five years back, the ratio of their ages was 2 : 3. What is the present age (in years) of A?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 15.
Present ages:
Let A's present age be 3x.
Let B's present age be 4x.
Five years ago:
A's age was 3x - 5.
B's age was 4x - 5.
Form the equation based on the given ratio:
Five years ago, the ratio of their ages was 2:3, so:
(3x - 5) / (4x - 5) = 2/3
Solve the equation:
Cross-multiply: 3(3x - 5) = 2(4x - 5)
Expand: 9x - 15 = 8x - 10
Simplify: 9x - 8x = 15 - 10
Solve for x: x = 5
Find A's present age:
A's present age = 3x = 3 * 5 = 15 years
Therefore, A's present age is 15 years.