Question

the prise of oil per kg increased from rs 25 to rs 30 by what percent should its consumption be decreased to maintain the same expenditure on oil as before​

Answer 1

price of oil per kg and consumption ar inversely proportional. So let xkg be the previous consumption and ykg be the new consumption.

so 25/30=y/x.

or, y=25x/30

thus, percentage of consumption to be decreased=(x-25x/30)×100/x%=16⅔%

Answer 2

Answer: Our required percent would be $16\dfrac{2}{3}\%$

Step-by-step explanation:

Since we have given that

Price of oil per kg = Rs. 25

Price of oil after increment per kg = Rs. 30

So, by what percent , consumption should be decreased to maintain the same expenditure on oil as before.

So, the percentage would be

$\dfrac{30-25}{30}\times 100\\\\=\dfrac{5}{30}\times 100\\\\=\dfrac{1}{6}\times 100\\\\=16\dfrac{2}{3}\%$

Hence, our required percent would be $16\dfrac{2}{3}\%$