Doubling the selling price after a 10% profit — resulting profit percent A seller makes a 10% profit at a certain selling price. If he doubles that selling price, what will be his new profit percentage?

Introduction / Context:
Profit percent is always computed on cost price (CP). If the initial selling price yields a 10% profit, that fixes CP relative to the original SP. Doubling the SP then yields a straightforward new margin over the same CP.

Given Data / Assumptions:

• Let CP = x.
• Initial SP1 = x × 1.10.
• New SP2 = 2 × SP1 = 2.20x.

Concept / Approach:
New profit% = ((SP2 − CP)/CP) × 100 = ((2.20x − x)/x) × 100 = 120%.

Step-by-Step Solution:
SP1 gives 10% profit ⇒ SP1 = 1.10x.Doubling SP ⇒ SP2 = 2.20x.Profit% = (1.20x/x) × 100 = 120%.

Verification / Alternative check:
Example: Take x = 100. SP1 = 110. Doubling ⇒ SP2 = 220. Profit = 120 on cost 100 ⇒ 120%.

Why Other Options Are Wrong:
20% and 60% understate; 100% implies doubling from CP, not from SP; 80% still too low.

Common Pitfalls:
Applying the second increase on SP rather than computing profit relative to CP, or adding 100 percentage points incorrectly.

Final Answer:
120%