nkmungila wrote:
Due to a sudden 20% increase in price, one is now able to buy 4 gallons lesser oil than earlier on the same expenditure of
$600. What is the dollar increase in the price of oil per gallon?
A. $2
B. $5
C. $10
D. $20
E. $25
We can let the original number of gallons of oil = n and the original price = p; thus:
np = 600
and
(1.2p)(n - 4) = 600
1.2np - 4.8p = 600
Substituting 600 for np in the above equation, we have:
1.2(600) - 4.8p = 600
720 - 4.8p = 600
120 = 4.8p
25 = p
The old price was 25, and the new price is 20% more: 25 x 1.2 = 30. Thus, the increase in price is 5 dollars.
Answer: B
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