Question 7 (Multiple Choice Worth 2 points)

A soda company would like to replace the label on a can of soda with a radius of [tex]$4 \frac{1}{4} \text{ cm}$[/tex]. If the label touches end to end with no overlap, what is the length of the label? Use [tex]\frac{22}{7}[/tex] for [tex]\pi[/tex].

A. [tex]\frac{187}{14} \text{ cm}[/tex]
B. [tex]\frac{187}{7} \text{ cm}[/tex]
C. [tex]\frac{187}{56} \text{ cm}[/tex]
D. [tex]\frac{187}{28} \text{ cm}[/tex]



Answer :

Sure, let’s work through this problem step-by-step to determine the length of the label:

1. Identify the radius: The radius of the soda can is given as [tex]\(4 \frac{1}{4} \)[/tex] cm. To make calculations easier, convert this mixed fraction into an improper fraction or a decimal.
[tex]\[ 4 \frac{1}{4} = 4 + \frac{1}{4} = 4 + 0.25 = 4.25 \text{ cm} \][/tex]

2. Circumference formula: To find the length of the label, we need the circumference of the soda can, which can be calculated using the formula:
[tex]\[ C = 2\pi r \][/tex]
where [tex]\(C\)[/tex] is the circumference, [tex]\(\pi\)[/tex] is approximately [tex]\(\frac{22}{7}\)[/tex], and [tex]\(r\)[/tex] is the radius.

3. Substitute the values: Substitute [tex]\( r = 4.25 \)[/tex] cm and [tex]\(\pi = \frac{22}{7}\)[/tex] into the formula:
[tex]\[ C = 2 \times \frac{22}{7} \times 4.25 \][/tex]

4. Perform the multiplication:
[tex]\[ C = 2 \times \frac{22}{7} \times 4.25 \][/tex]

5. Multiply step-by-step:
[tex]\[ 2 \times \frac{22}{7} = \frac{44}{7} \][/tex]
[tex]\[ \frac{44}{7} \times 4.25 = \frac{44 \times 4.25}{7} = \frac{44 \times \frac{17}{4}}{7} \][/tex]
because [tex]\(4.25 = \frac{17}{4}\)[/tex].

6. Simplify multiplication:
[tex]\[ \frac{44 \times 17}{4 \times 7} = \frac{748}{28} \][/tex]

7. Final result: Simplify [tex]\(\frac{748}{28}\)[/tex]:
[tex]\[ \frac{748}{28} = 26.714285714285715 \][/tex]

8. Convert the numerical result back into one of the provided choices:
[tex]\[ 26.714285714285715 = \frac{748}{28} \][/tex]
Simplifying this fraction, we get:
[tex]\[ \frac{748}{28} = \frac{187}{7} \][/tex]

Therefore, the correct length of the label, using [tex]\(\frac{22}{7}\)[/tex] for [tex]\(\pi\)[/tex], is:
[tex]\[ \boxed{\frac{187}{7} \text{ cm}} \][/tex]