A dishonest dealer sells a product at 11% loss on cost price, but uses 22% less weight. What is his percentage profit or loss?

14.1% gain

Let his good contains 1 Kg

Its actual weight is 22% less of 1000 gm = 780 gm

 Let C.P. of each gm be Rs. 1

Then C.P of 780  gm = Rs. 780

S.P. =89% of C.P. of 1 kg = 890

Profit = 890 – 780 = 110

Profit % = 110 × \(\frac{100}{780}\)  = 14.1%