A person bought 25 pens for Rs.25 . He sold 14 of them at a loss of 50%. He wants to gain 10% on the whole. Then his gain percent on the remaining pens should be:

86\(\frac{4}{11}\)%

Price of 25 pens = Rs.25

Price of 14 pen = Rs.14

ATQ,

S.P. 14 pen @50% loss = Rs.7

To earn 10% profit on all pens,

S.P. should be Rs.27.5 (i.e. 110% of 25)

Now profit is to be earn on remaining 11 pens = Rs.9.5

Therefore,

gain % on the remaining 10 pens =  \(\frac{9.5}{11}\) × 100 = 86\(\frac{4}{11}\)%