JAMB 2022 Mathematics · Question 24

If a dress is sold for #3800.00 at 20% discount. what is its original price?

Options

  1. A.#3,000.00
  2. B.#4,000.00
  3. C.#5,000.00
  4. D.#4,750.00

Answer: D. #4,750.00

Explanation written with AI and checked against the answer key

Analysis

To find the original price of the dress, we need to understand that the selling price represents the original price minus the discount. Since the discount is 20%, the selling price is actually 80% of the original price.

Concept

When an item is sold at a discount, the relationship is: Selling Price = Original Price × (100% - Discount Percentage)

Let xx be the original price. The discount is 20%, so the customer pays 80% of the original price. Mathematically: 0.80×x=Selling Price0.80 \times x = \text{Selling Price}

Step-by-Step Solution
  1. Identify the given values: • Selling Price = #3,800.00 • Discount = 20% • Percentage paid = 100% - 20% = 80% (or 0.8 in decimal form)
  1. Set up the equation: 0.8×x=38000.8 \times x = 3800
  1. Solve for xx: x=38000.8x = \frac{3800}{0.8}
  1. Perform the division: To make it easier, multiply both numerator and denominator by 10: x=380008x = \frac{38000}{8} 38000÷8=475038000 \div 8 = 4750

The original price of the dress is #4,750.00.

Conclusion

Comparing our result with the provided options, the correct choice is D.

Exam Tip

Whenever you are given a selling price after a discount, do not just add 20% of the selling price to the selling price. That is a common mistake! Always remember that the discount is calculated based on the original price, not the reduced price. If you are ever unsure, check your answer by calculating 20% of your result and subtracting it—if you get the original selling price, you are correct!

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