The usage of sugar of a family of 3 adults and 2 children

swerve wrote:The usage of sugar of a family of 3 adults and 2 children was 13 kg in a certain month. If the monthly average usage of sugar for an adult is 3 kg and for a child is 1 kg, by what percent the specific month’s sugar consumption was more or less than the typical usage?

A. 22.22% more
B. 18.18% more
C. 15.38% more
D. 15.38% less
E. 18.18% less

The OA is B.

Source: e-GMAT

Monthly average consumption of sugar = 3*3 + 2*1 = 11 kg
Consuption of sugar in the ceratin month = 11 kg

Thus, the specific month’s sugar consumption was [(13 – 11)/11]*100% = 18.18% more than the typical usage.

The correct answer: B

Hope this helps!

-Jay
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swerve wrote:The usage of sugar of a family of 3 adults and 2 children was 13 kg in a certain month. If the monthly average usage of sugar for an adult is 3 kg and for a child is 1 kg, by what percent the specific month’s sugar consumption was more or less than the typical usage?

A. 22.22% more
B. 18.18% more
C. 15.38% more
D. 15.38% less
E. 18.18% less

The family average consumption of sugar is 3 x 3 + 2 x 1 = 11 kg. Therefore, for the month with 13 kg consumption of sugar, it exceeds the typical monthly consumption by:

(13 - 11)/11 x 100 = 2/11 x 100 = 18.18 percent

Answer: B

Hi All,

We're told that the usage of sugar of a family of 3 adults and 2 children was 13 kg in a certain month and the monthly AVERAGE usage of sugar for an adult is 3 kg and for a child is 1 kg. We're asked by what percent THIS specific month’s sugar consumption was more or less than the typical usage. The wording of this question is 'clunky', but the intent is to test us on the Percentage Change Formula:

Percent Change = (New - Old)/(Old) = Difference/Original

With 3 adults and 2 children, the AVERAGE monthly usage would give us a total of (3)(3) + (2)(1) = 11 kg of sugar.
This month, the total is 13 kg though, which is clearly an INCREASE.
The percent change is (13 - 11)/11 = 2/11 = a little more than 18%

Final Answer: B

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Rich