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

2.

Required average	= 67 x 2 + 35 x 2 + 6 x 3 2 + 2 + 3
	= 134 + 70 + 18 7
	= 222 7
option B	= 31  5 years.                           7