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

Expenditure/Population:
= (1.2 * 10^12)/(240 * 10^6)
= (12 * 10^11)/(24 * 10^7)
= (12/24)*(10^11/10^7)
= 1/2 * 10^4
= 5,000.

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

5000

= (1.2 * 10¹²)/(240 million)
= (1.2 * 10¹²)/(240 * 10�)
= (1.2 * 10³ * 10�)/(240 * 10�)
= (1.2 * 10³ * 10�)/(240 * 10�)
= (1200 * 10�)/(240 * 10�)
= (1200/240)(10�/10�)
= (5)(10³)
= (5)(1000)
= 5000

ftfy ^ ^