Correct Answer - Option 3 : 7 months
Given:
Investment of Anil = Rs. 2500 for 12 months
Investment of Virat = Rs. 4000
Ratio of profit at the end of year = 3 ∶ 2
Concept used:
Ratio of product of time and investment = Ratio of profit
Calculation:
Let, Virat joined after t months
Investment of Anil for 1 year = Rs. 2500 for 12 months = Rs. (2500 × 12) = Rs. 30000
Investment of Virat for 1 year = Rs. 4000 for T months = Rs. 4000T, where T = (12 – t)
Ratio of product of time and investment = Ratio of profit
Ratio of profit = 30000 ∶ 4000T = 15 ∶ 2T = 3 ∶ 2 (Given)
Equating two ratios, 15/2T = 3/2
⇒ T = 15/3 = 5
⇒ t = 12 – 5 = 7
∴ Virat joined after 7 months.