If the selling price is doubled, the profit triples. Find the profit %:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 100%
Profit = selling price − cost price, and the cost price does not change when the selling price is doubled. Writing the cost price as \(C\) and the selling price as \(S\):
Original profit \(=S-C\); new profit \(=2S-C\)
The new profit is three times the old: \(2S-C=3(S-C)\)
\(2S-C=3S-3C\), so \(S=2C\)
Profit \(=2C-C=C\), that is, equal to the cost price: profit \(=100\%\)