A shopkeeper sells goods at 82% loss on cost price but uses 28% less weight. What is his percentage profit or loss?

Let the actual cost price (CP) of 1000g of goods be Rs. 1000.
The shopkeeper sells it at an 82% loss on the cost price.

Selling Price (SP)=1000×(1−
100
82
​
)=1000×
100
18
​
=Rs. 180
However, he uses 28% less weight:

Weight actually given=1000×(1−
100
28
​
)=720g
The cost price of 720g of goods to the shopkeeper is:

Effective CP=Rs. 720
Now, we calculate the overall profit or loss percentage:

Loss=Effective CP−SP=720−180=Rs. 540
Loss %=(
Effective CP
Loss
​
)×100=(
720
540
​
)×100=
4
3
​
×100=75%
Thus, the shopkeeper incurs a 75% loss.