rohit8865 wrote:
Bunuel wrote:
If the price of gasoline increases by 25% and Ron intends to spend only 15% more on gasoline, by how much percent should he reduce the quantity of gasoline that he buys?
A. 6.66%
B. 8%
C. 10%
D. 12%
E. 12.5%
Let he consumes 10 ltr
RS 10 so he spends Rs 100
As er question he intends to spend 15% more (of 100 in our case)=Rs 115
and price increased by 25% =Rs. 12.5 (10+25% of 10)
let he reduces quantity by X lts. then consumed(new reduced) quantity= 10(1-X/100)
Spending amount=Price of gasoline*Quantity
115=12.5*10(1-X/100)
X=8%
Ans B
For wondering minds, "Rs" in the solution above is short for "Rupee" - a monetary unit in India.
This is how I solved...
Let the initial cost of gas before the hike be $100/gal
Price hike given = 25%
=> New gas price per gallon is $125
Also given, Ron can only spend 15% more of what he used to afford. It is to be understood from the prompt that he was able to afford a full gallon (which means he used to get 1 gal of gas) before the hike. So, he was able to afford $100 before the hike but now he can only afford 15% more of $100. Therefore, he could only pay $115.
You get what you pay, so instead of getting a full gallon of gas, he will now only get 0.92 gal [For $125 you get 1 gal, for $115 - how many? => \(\frac{1}{125}\)*115].
Finally, find the percentage decrease in the amount of gas from before and now.
Percentage Decrease =\(\frac{0.92 - 1}{1}\)*100