Concept: The question tests on basics of Percentage (Profit/Loss)

Solution:
 

Let Price of the table = T and that of a chair = C

Price of table T = 350 + C ... (1)

Also 7T + 7C = 4550 or T + C = 650 ... (2)

Putting (1) in (2) 350 + 2C = 650

2C = 300 or C = 150

Therefore price of a table = 150 + 350 = 500

% Decrease = DifferenceLarger Number100=500−150500100=70DifferenceLarger Number100=500−150500100=70%

Option B