Question

a local Dunkin Donuts shop reported that its cells have increased exactly 18% per year for the last 2 years. This year sells were 82,330. What were Dunkin Donuts sells 2 years ago(round each years sales to the nearest dollar)​

Answer 1

$59,128

Explanation:

Whenever we increase a number by a percentage, follow the example below:

• if we increase a number "x" by, say, 15%, we will multiply by 1.15
• if we increase a number "y" by, say, 47%, we will multiply by 1.47

Now, similarly, if we were to increase a number by 18%, we will multiply by 1.18. Given this, let's take a look at the scenario:

2 years ago sales = x [this is what we need to find, so we let is equal to x]

1 year ago sales = increased by 18% from previous, so 1.18x

Now = increased by 18% from previous [1 year ago], so 1.18 (1.18x) which is equal to 82,330

Thus, our equation becomes
`1.18(1.18x)=82,330`

Now, we multiply/divide and solve:

`1.18(1.18x)=82,330\\1.3924x=82,330\\x=59,128`

Thus, 2 years ago, Dunkin Donut's sales were around $59,128