Rapid Revision · Quantitative Aptitude
Every profit and loss question is a percentages question wearing a shop apron. Anchor everything to cost price and you cannot get lost.
If you read nothing else tonight, read these 6 lines.
Every formula for profit & loss in one place, each labelled so you know exactly when to reach for it. Screenshot it the night before.
Profit / Loss
Profit = SP - CP Loss = CP - SP
Profit percent
profit% = (profit / CP) x 100
Gain and loss % are ALWAYS on cost price unless stated otherwise.
SP from CP
SP = CP x (100 + gain%) / 100
CP from SP
CP = SP x 100 / (100 + gain%)
Discount
SP = MP x (100 - discount%) / 100
Same SP, +x% and -x%
net result = LOSS of (x / 10)^2 %
Two items sold at the same price, one at +x% one at -x%: never break even.
8 cards, each one idea: what it is, a worked example, and the trap to dodge.
CP = what it cost, MP = the sticker, SP = what it sold for. Profit and loss compare SP with CP; discount compares SP with MP.
CP 80, MP 120, SP 96: discount 20% (on 120), profit 20% (on 80).
Trap: Profit percent is on CP, discount percent is on MP; mixing bases is the classic error.
SP = CP x (100 + gain%)/100 for profit, CP x (100 - loss%)/100 for loss. Reverse it to get CP from SP.
CP 250 at 12% profit: SP = 250 x 1.12 = 280.
Mark up m% then give d% discount: net% = m - d - md/100. It is the successive-change formula again.
Mark up 40%, discount 20%: 40 - 20 - 8 = +12% profit.
Trap: A 40% markup with a 40% discount is a 16% LOSS, not break-even.
Two discounts a% and b% combine to a + b - ab/100 (single equivalent discount).
20% and 10%: 20 + 10 - 2 = 28%, not 30%.
Two items sold at the same price, one at x% profit and the other at x% loss: the seller always loses x^2/100 % overall.
x = 10: net loss = 100/100 = 1%.
Trap: The answer is never 'no profit no loss'; it is always a loss.
A trader sells at cost price but gives less quantity. Gain% = error/(true - error) x 100.
900 g sold as 1 kg: gain = 100/900 x 100 = 11.11%.
When both markup and discount are known, run CP -> MP -> SP with multiplying factors and compare ends.
CP 100, MP 100 x 1.5 = 150, SP at 30% discount = 105: profit 5%.
'Sold at cost price' plus any hidden trick (false weight, free item bundling) still means a real gain. Compute what the buyer actually gets per rupee.
Trap: If the question says no profit, look for the hidden quantity trick before answering 0%.
A recap is not practice. These are the creators we rate for real depth on profit & loss; full credit to each.
Each recap takes 3 minutes; the full set covers everything the first round tests. And when the test is cleared, your resume takes the next screen.
Original content by OptiResume; facts and formulas are common knowledge, the wording is ours. Go-deeper links go to creators we rate; we are not affiliated with them.