Question

Noah thinks the answers to these two questions will be the same. Do you agree with him? Explain your reasoning. This year, a herd of bison had a 10% increase in population. If there were 550 bison in the herd last year, how many are in the herd this year? This year, another herd of bison had a 10% decrease in population. If there are 550 bison in the herd this year, how many bison were there last year?

Answer 1

Answer: No, She is not right.

Explanation:

First question:

Initial number of bison = 550

After increasing 10% than the initial number of bison, the new number of bison after one year= Initial number of bison + 10 % of the initial number of bison

=
`110\% \text{ of the initial number of bison}`

=
`110\% \text{ of }550`

=
`(110* 550)/(100)`

=
`(60500)/(100)`

=
`605`

Second question:

Let Initial number of bison = x

After decreasing 10% than the initial number of bison, the new number of bison after one year= Initial number of bison - 10 % f the initial number of bison

=
`90\% \text{ of the initial number of bison}`

=
`90\% \text{ of } x`

=
`(90* x)/(100)`

=
`(9x)/(10)`

According to the question,

`(9x)/(10)=550`

`x=(5500)/(9)=611.11\approx 611`

Since, 605 ≠ 611

Therefore, Both questions have different answer.

⇒ Noah is not correct.