Question

“Donations to an annual fundraiser are 15% greater this year then last year. Last year, donations were 10% greater than a year before. The amount raised this year is $10,120. How much was raised 2 years ago?”

Answer 1

Answer: The amount raised 2 years ago was $8000.

Explanation:

Since we have given that

The amount raised this year = $10120

Let the amount that was raised 2 years ago be 'x'.

There is increment this year than last year = 15%

There is increment last year than a year before = 10%

So, We need to find the value of x i.e. the original donation 2 years ago was:

So, According to question, our equation becomes

`x* (100+10)/(100)* (100+15)/(100)=10120\\\\x* (110)/(100)* (115)/(100)=10120\\\\x* 1.1* 1.15=10120\\\\x=(10120)/(1.1* 1.15)=8000\\\\x=\$8000`

Hence, the amount raised 2 years ago was $8000.

Answer 2

Answer: Amount was raised 2 years ago was $8000.

Explanation:

Since we have given that

Amount raised this year = $10120

According to question,

Donation were 10% greater than a year before .

Donation were 15% greater that year than its previous year i.e. 2 years ago.

Let amount raised 2 years ago be x

So, it becomes,

`x* (115)/(100)* (110)/(100)=\$10120\\\\x=10120* (100)/(115)* (100)/(110)\\\\x=\$8000`

Hence, Amount was raised 2 years ago was $8000.