Profit and Loss: Concepts, Formulas, and Clear Examples
CP (cost price) and SP (selling price) drive profit and loss . Percent always on CP unless stem says on SP.
Successive discounts multiply on marked price; false weights scale effective CP.
Partnership with dishonest dealer: actual CP vs claimed weight.
Basic profit percent
Profit %
SP from profit%
Example — 20% profit
CP=250, profit 20%. SP = .
Loss and reverse CP
Loss %
CP from SP
Marked price and discount
After discount d%
Two discounts
False weights
Seller uses weight w instead of W
Break even
- SP = CP + overheads when given.
- 0% profit at SP equal to total cost.
Exam traps
- Profit% on SP wording changes denominator.
- Compare CP before deciding cheaper deal.
Step-by-step method for exam questions
- Label CP, SP, MP, discount, profit/loss %.
- Convert % to multiplier on correct base.
- Chain discounts on MP.
- Adjust CP for false weight if any.
- Compute numeric SP/CP/profit.
- Select option.
Formula cheat sheet
| Situation | Formula | When to use |
|---|---|---|
| Profit p% on CP | Standard | |
| Loss l% on CP | Loss sale | |
| Find CP from SP | Reverse | |
| Discount on MP | Marked price | |
| False weight | Effective CP scales | Short weight |
Frequently asked questions
Profit% on SP?
Use when explicitly on SP.
10% off then 10% off?
Net 19% off MP, not 20%.
Same SP, different CP?
Higher CP ⇒ lower profit%.
GST in stem?
Follow whether tax included in SP/CP labels.
Practice on this platform
Use 4 practice sets (10 MCQs, detailed solution after each answer) and 2 timed mocks (20 minutes) on this topic to convert formulas into speed and accuracy.