The price of fuel decreases by 35%, 10% and 30% in three successive months, but increases by 65% 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?

Correct option is B

Given:
Decreases by 35%
Decreases by 10%
Decreases by 30%
Increases by 65%

Concept Used:

Successive percentage decrease or increase;

​$$\text{New Price} = \text{Original Price} \times \left( 1 + \frac{\text{Change}_1}{100} \right) \times \left( 1 + \frac{\text{Change}_2}{100} \right) \times \left( 1 + \frac{\text{Change}_3}{100} \right) \times \left( 1 + \frac{\text{Change}_4}{100} \right)$$​

Solution:

Applying the formula;

= $$100 \times \left(1 - \frac{35}{100} \right) \times \left(1 - \frac{10}{100} \right)\times \left(1 - \frac{30}{100} \right) \times \left(1 + \frac{65}{100} \right)$$

= $$100\times \left( \frac{65}{100} \right)\times \left( \frac{90}{100} \right) \times \left( \frac{70}{100} \right) \times \left( \frac{165}{100} \right)$$ 

= 67.57%

So, the change in price decreases by = 100 - 67.57% = 32.43%