Problem Solving

During a 3-year period, the Gross Domestic Product (GDP) of Country U changed by what percvent from the first year to the second year?

1) The GDP of Country U enjoyed a constant growth rate both from the first to the second year and from the second to the third year in a certain 3-year period.

2)The GDP during the first year from 235 billion dollars. It increased to 338.4 billion dollars in the third year.


I know the answer is C, that you need both information for it to be sufficient but I'm having trouble with actually solving questions like this. When it asks questions like "changed by what percent." Can someone break it down for me to actually solving this and if have any tip or secrets for future questions similar to this and what equation to use that would be greatly appreciated.

nickhar130 wrote:During a 3-year period, the Gross Domestic Product (GDP) of Country U changed by what percvent from the first year to the second year?

1) The GDP of Country U enjoyed a constant growth rate both from the first to the second year and from the second to the third year in a certain 3-year period.

2)The GDP during the first year from 235 billion dollars. It increased to 338.4 billion dollars in the third year.


I know the answer is C, that you need both information for it to be sufficient but I'm having trouble with actually solving questions like this. When it asks questions like "changed by what percent." Can someone break it down for me to actually solving this and if have any tip or secrets for future questions similar to this and what equation to use that would be greatly appreciated.

ehhh, i think it says if the first year, GDP=100, the second year it increase 10% so it will be 110% (=100% of the second year compared to the third year)
because the increase GDP is constant thus the third year, it will be 110 (%)
Thus, from the first to the third GDP= 110*110/100=121% =1,21
from all above, and the statement 2, does it help you to find the way to solve the problem?

nickhar130 wrote:During a 3-year period, the Gross Domestic Product (GDP) of Country U changed by what percvent from the first year to the second year?

1) The GDP of Country U enjoyed a constant growth rate both from the first to the second year and from the second to the third year in a certain 3-year period.

2)The GDP during the first year from 235 billion dollars. It increased to 338.4 billion dollars in the third year.


I know the answer is C, that you need both information for it to be sufficient but I'm having trouble with actually solving questions like this. When it asks questions like "changed by what percent." Can someone break it down for me to actually solving this and if have any tip or secrets for future questions similar to this and what equation to use that would be greatly appreciated.

You posted in problem solving sec.
Please move this to DS.

statement 2 says that 1st year = 235 and 3rd year = 338.4

So 2nd year = (338.4 - 235)/2 + 235 = 286.7

...but how do i answer the question "Country U changed by what percvent from the first year to the second year?"

is it 1st year(1 + x) = 2nd year
235(1 + x) = 286.7

and therefore x is 22%? im not sure.

The equation basically is

235 ( 1 + x/100) (1+ x/100)=338.4

Solve for X to the percentage increase in a year.