manu.pant wrote:A certain country had a total annual expenditure of
$1.2 × 10^12 last year. If the population of the country
was 240 million last year, what was the per capita
expenditure?
Ans is 5000, but I think it should be 500
Source: OG12, Prob Solving 133
A certain country had a total annual expenditure of $1.2 x 10^12 last year. If the population of the country was 240 million last year, what was the per capita expenditure?
A) $500
B) $1,000
C) $2,000
D) $3,000
E) $5,000
Solution:
One key to solving this problem is to accurately translate what is being asked into a mathematical equation. We need to determine the "per capita expenditure," which is obtained by the formula:
Per capita expenditure = (Total annual expenditure)/(Total population)
The first step is to express 240 million as a number times a power of 10, since the other number is in such a format.
240 million = 240,000,000
Since we have a 24 with 7 zeroes we can write this number as:
24 x 10^7
Next, we adjust 1.2 x 10^12 to make it a more useful number in our expression.
1.2 x 10^12 = 120 x 10^10
We now can solve:
Per capita expenditure = (Total annual expenditure)/(Total population)
Per capita expenditure = (120 x 10^10)/(24 x 10^7)
Per capita expenditure = 5 x 10^3
Per capita expenditure = 5 x 1,000
Per capita expenditure = 5,000
Answer:
E
