A dishonest shopkeeper sells his grocery using weights 10% less than true weights and makes a profit of 30%. Find his total gain percentage.

Let the weight of the grocery bag be 1000 gm.
Now, the shopkeeper sells his grocery using weights 10% less than true weights.
Hence, actual weight of bag = 90% of 1000 gm = 900 gm
If each gram = Tk.1, C.P. of each bag containing 900 gm = Tk. 900
The shopkeeper sells with a gain of 30% on true C.P.

Calculate the S.P.
Selling price = 100 + gain% × C.P.
Therefore,
Selling price = (130/100) × Tk. 1000
= Tk. 1300
Gain = S.P. - C.P. = 1300 - 900 = Tk. 400
Gain% = (400/900) × 100
= 44.44%