The ratio of age of Rohan and Sohan is 8 : 9. After 9 years, this will become 19 : 21. If Arun is 3 years younger to Sohan, then what is present age of Arun?

51 

Ratio of age of Rohan and Sohan = 8 : 9

After 9 years from present = 19 : 21

ATQ,

\(\frac{8R + 9}{9R + 9}\) = \(\frac{19}{21}\)

⇒ 168R + (21 × 9) = 171R + (19 × 9)

⇒ 3R = (21 - 19) × 9 = 18

⇒ 1R = 6

Present age of Sohan = (9 × 6) = 54

Age of Arun = 54 - 3 = 51