Amount Mr. Virmani paid to purchase the house = Rs. 365000
Amount he spent on repair = Rs. 135000
Total amount he spent on the house (CP) = Rs. (365000 + 135000) = Rs. 500000
SP of the house = Rs. 550000
Gain = SP - CP = Rs. (550000 - 500000) = Rs. 50000
Gain % = (Gain/CP) × 100 = (50000/500000) × 100 = 5000000/500000 = 10%