A, B and C entered into a partnership. A invested Rs. 2560 and B invested Rs. 2000. At the end of the year, they gained Rs. 1105, out of which A got Rs. 320. C's capital was ?

A. Rs. 2840

B. Rs. 4028

C. Rs. 4280

D. Rs. 4820

Answer: Option C

Solution(By Examveda Team)

Let C's capital be Rs. x
Then,
A : B : C = 2560 : 2000 : x
$$\eqalign{ & {\text{A's share}} \cr & = {\text{Rs}}{\text{.}}\left( {1105 \times \frac{{2560}}{{4560 + x}}} \right) \cr & \therefore 1105 \times \frac{{2560}}{{4560 + x}} = 320 \cr & \Rightarrow 320x + 1459200 = 2828800 \cr & \Rightarrow 320x = 1369600 \cr & \Rightarrow x = 4280 \cr} $$