The ratio of the present ages of Ram and Shyam is 3 : 4, and 4 years ago the ratio was 2 : 3. What will be the ratio of the ages of Ram and Shyam 4 years from now?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 4 : 5.
Let present ages be
Ram = 3x
Shyam = 4x
4 years ago Ram's age = 3x − 4 and Shyam's age = 4x − 4
⇒ (3x − 4)(4x − 4) = 2/3
⇒ 3(3x − 4) = 2(4x − 4) ⇒ 9x − 12 = 8x − 8 ⇒ 9x − 8x = − 8 + 12 ⇒ x = 4
Present Ages Ram = 3x = 12 and Shyam = 4x = 16
Ages 4 years from now
Ram = 12 + 4 = 16
Shyam = 16 + 4 = 20
Ratio = 16/20 = 4/5 = 4 : 5