
Shortcut Trick
Effective Discount % = [1 − (Paid Price % ÷ Received Quantity %)] × 100
Paid Price % = 100% − 15% = 85%
Received Quantity % = 100% − 10% = 90%
Effective Multiplier = 85 ÷ 90 = 17/18
Effective Discount % = (1 − 17/18) × 100 = 1/18 × 100 = 5.55...%
Rounding to one decimal place, we get 5.6%.
∴ The correct answer is 5.6%.

Alternate Method
Given: Total rice = 25 kg, Price = ₹1,400, Discount offered = 15%, Quantity cheated = 10% less.
Formula: Effective Price per unit = Total Paid ÷ Total Quantity Received

⇒ Original rate per kg = 1400 ÷ 25 = ₹56
⇒ Discounted total amount paid = 1400 − (15% of 1400) = 1400 − 210 = ₹1,190
⇒ Actual quantity received by customer = 25 − (10% of 25) = 25 − 2.5 = 22.5 kg
⇒ Effective price paid per kg = 1190 ÷ 22.5 = ₹52.888...
⇒ Discount amount per kg = 56 − 52.888 = ₹3.111
⇒ Effective Discount % = (3.111 ÷ 56) × 100 = 5.555...%
⇒ Correct to one decimal place = 5.6%
∴ The correct answer is 5.6%.

Additional Information
Dishonest Dealer Profit Concept
Profit % = [ (True Weight − Faulty Weight) ÷ Faulty Weight ] × 100. This is used when the dealer cheats on quantity while selling.
Successive Percentage Changes
For two successive changes of a% and b%, the net change is given by [ a + b + (ab ÷ 100) ] %. For discounts, use negative values.
Effective Rate Method
Effective Discount = [ 1 − (Ratio of Final Cost ÷ Ratio of Final Quantity) ] × 100. This helps solve combined price-quantity variation problems quickly.