Question

Last year the income for a business was 2,000,000. This year the income grew 15%. What was the income for the business this year?

Answer 1

The income in 2010 is 2.3 million

Explanation:

The formula for determining rate of change over time is:

`p/100 = (N - O)/O`

Where `p` is the percentage change (for this problem `15`)

Where `O` is the old value (for this problem `2000000`

Where `N` is the new value (what we are solving for in this problem)

Substituting and solving for `N`:

`15/100 = (N - 2000000)/2000000`

`15/100 = N/2000000 - 2000000/2000000`

`15/100 = N/2000000 - 1`

`15/100 + color(red)(1) = N/2000000 - 1 + color(red)(1)`

`15/100 + (color(red)(1) * color(blue)(100/100)) = N/2000000 - 0`

`15/100 + 100/100 = N/2000000`

`115/100 = n/2000000`

`color(red)(2000000) * 115/100 = color(red)(2000000) * N/2000000`

`230000000/100 = cancel(color(red)(2000000)) * N/color(red)(cancel(color(black)(2000000)))`

`2,300,000 = N`