Question

b. After a 25% discount, the price of a T-shirt was $12. What was the price before
the discount?
c. Compared to last year, the population of Boom Town has increased by 25%. The
population is now 6,600. What was the population last year?
**Key Takeaway:

Answer 1

The price before  the discount is $ 16

The population last year is 5280

Solution:

B) After a 25% discount, the price of a T-shirt was $12. What was the price before  the discount?

Given that after a 25% discount, the price of a T-shirt was $12.  

We have to find what was the price before the discount?  

Now, we know that,

original price – discount = selling price

Original price – 25% of original price = $12

Let the original price be "a"

$\begin{array}{l}{\mathrm{a}-25 \% \text { of } \mathrm{a}=12} \\\\ {a-\frac{25}{100} \times a=12} \\\\ {a\left(1-\frac{25}{100}\right)=12} \\\\ {a\left(1-\frac{1}{4}\right)=12} \\\\ {a\left(1-\frac{1}{4}\right)=12} \\\\ {a\left(\frac{3}{4}\right)=12} \\\\ {a=12 \times \frac{4}{3}=16}\end{array}$

Thus the original price is $ 16

C) Compared to last year, the population of Boom Town has increased by 25%. The  population is now 6,600. What was the population last year?

Last year population + 25% of last year population = present population.

$\begin{array}{l}{ \text { Last year population( }100 \%+25 \%)=6600} \\\\ {\text { Last year population } \times 125 \%=6600} \\\\ {\text { Last year population } \frac{125}{100}=6600} \\\\ {\text { Last year population }=6600 \times \frac{4}{5}} \\\\ {\text { Last year population }=660 \times 2 \times 4} \\\\ {\text { Last year population }=5280}\end{array}$

Thus the last year population is 5280

Answer 2

After a 25% discount, the price of a T-shirt was $12 then the price before  the discount is $16, and the population of Boom Town has increased by 25%. The  population is now 6,600 so, the population last year is 5280 and this can be determined by using the unitary method.

B)

Given:  

After a 25% discount, the price of a T-shirt was $12.

By using the unitary method the price of the T-shirt before the discount can be determined.

Given that after a 25% discount, the price of a T-shirt was $12 so, the price of $12 is 75%. Therefore, the price of the T-shirt before the discount is:

$=\dfrac{12}{75}\times 100$

= $16

C)

Given -

• The population of Boom Town has increased by 25%.
• The  population is now 6,600.

Given that the population is increased by 25% that means the population of 6600 is 125% of the population of last year. Therefore, the population of last year will be:

$=\dfrac{6600}{125}\times 100$

= 5280

The population of the last year is 5280.

For more information, refer to the link given below:

https://brainly.com/question/14793162