Question

The price of fuel decreases by 40%, 50% and 15% in three successive months, but increases by 40% in the fourth month. What is the percentage increase/decrease in the price of fuel in the fourth month as compared to its original price?

• A. Decreases by 64.3%
• B. Increases by 65.91%
• C. Increases by 65.47%
• D. Decreases by 69.09%

Answer 1

Answer:

A. Decreases by 64.3%

Assume the original price = 100 (for easy calculation).

Apply successive changes:

1. Decrease by 40%
   
   $100 \times 0.60 = 60$
   

2. Decrease by 50%
   $60 \times 0.50 = 30$
   

3. Decrease by 15%
   $30 \times 0.85 = 25.5$
   

4. Increase by 40%
   $25.5 \times 1.40 = 35.7$
   

   Compare with original price:

• Original price = 100

• Final price = 35.7

  $\text{Change} = 35.7 - 100 = -64.3$
  

• Percentage change:

  $\frac{-64.3}{100} \times 100 = -64.3\%$
  

  Final Answer:

There is a 64.3% decrease in the price compared to the original price.