Correct Answer - Option 3 : 4 months
Given∶
Beyonce's investment = $ 84000
After some time Jackson invested = $ 63000
Total profit was divided in the ratio = 2 ∶ 1
Formula Used∶
Concept of the ratio of product of investment and time duration is equal to ratio of profit.
Calculation∶
We can assume that Jackson join into Business after x months.
So, Jackson invest into (12 - x) months.
Also, (Beyonce investment × time period) ∶ (Jackson investment × time period) = Ratio of their profit
⇒ (84000 × 12) / [63000 × (12 - x)] = 2/1
⇒ 84000 × 12 = 2× 63000 × (12 - x)
⇒ (42 × 12) / 63 = 12 - x
⇒ x = 12 - 8
⇒ x = 4
∴ Jackson joined Beyonce's Business after 4 months.