A and B started a business by investing ₹70,000 each. After 10 months A invests an additional amount of ₹40,000. After 2 more months B withdraws ₹20,000. After 2 more months a third person C joins the business and invests ₹40,000. If at the end of 2 years, C gets ₹7,500 as his share of profit, then what is A's share in the profit?

Profit ratio = Ratio of $$(investment\times\ duration)$$

According to the conditions given in the question, 

Profit Ratio of A, B and C :

 $$\left(70000\times\ 10\right)+110000\times\ 14\ :\ \left(70000\times12\right)+\left(50000\times\ 12\right)\ :\ \left(40000\times\ 10\right)$$

i.e; 2240 : 1440 : 400

i.e 112 : 72 : 20 

Given,

Profit share of C = 7500

20 units = 7500 

1 unit = 375

Share of A in the profit = $$375\times\ 112$$ = ₹42000

Hence, Option C is correct.