Correct Answer - Option 1 : Rs. 840
Given
By selling an article for Rs.720 a man loses 10%
Concept used
Profit and loss
Calculation
Loss = 10%
SP = 9 unit; CP = 10 unit
SP = Rs.720
9 unit = Rs.720
1 unit = 80
CP = 80 × 10
Cp = Rs.800
To gain 5% it should be sold at
SP = \(\frac{{800}}{{20}} × 21\)
SP = 40 × 21
SP = Rs.840