Given cost of 1 dozen roses = Rs. 2
Number of roses bought by the florist = 100 dozens
Thus, cost price of 100 dozen roses = 2 x 100 = Rs. 200
Roses left after discarding the mutilated ones = 80 dozens
Calculating the price at which the florist should sell the 80 dozen roses in order to make a profit of 20%, we have
Profit % = ((SP-CP)/CP) x100 = ((SP-200)/200) x 100
40 = SP – 200
SP = Rs. 240
Therefore, the SP of the roses should be Rs. 240/80 = Rs. 3 per dozen.