The average monthly income of A and B is Rs. 4050. The average monthly income of B and C is Rs. 5250 and the average monthly income of A and C is Rs. 4200. What is the monthly income of A?
Choose the correct choice:
A) 2000	B) 2500	C) 3000	D) 3500	E) 4000
Let monthly income of A = x   monthly income of B = y   monthly income of C = z   x + y = 2 × 4050 .... (Equation 1)   y + z = 2 × 5250 .... (Equation 2)   z + x = 2 × 4200 .... (Equation 3)   (Equation 1) + (Equation 3) - (Equation 2)   =&gt; x +y + x + z - (y + z) = (2 × 4050) + (2 × 4200) - (2 × 5250)   =&gt; 2x = 2(4050 + 4200 - 5250)   =&gt; x = 3000   i.e., Monthly income of A = 3000   ANSWER:3000
<result>C</result>
The average monthly income of A and B is Rs. 4050. The average monthly income of B and C is Rs. 5250 and the average monthly income of A and C is Rs. 4200. What is the monthly income of A?