SSC CHSL Model Paper 8

Let P, Q and R represent their respective monthly incomes. Then, we have:
P + Q = (5050 × 2) = 10100…(i)
Q + R = (6250 × 2) = 12500…(ii)
P + R = (5200 × 2) = 10400…(iii)
Adding Eq. (i), (ii) and (iii), we get:
2(P + Q + R) = 33000
⇒ P + Q + R = 16500 .. (iv)
Subtracting Eq. (ii) from (iv), we get P = 4000
∴ P's monthly income = Rs. 4000