Jeremy 2

Jeremy is digitally editing out some red-eye problems in the photos from his sister's birthday party. The eyes are small and hard to click on, so he zooms in on the photo from 100% to 400%. In the zoomed-in photo, the eyes are 3 cm wide. How many cm wide were the eyes before zooming?

Correct answer:

a =  0.75 cm

Step-by-step explanation:

$$\begin{gathered} r_1=100\%=\frac{100}{100}=\frac{1}{1}=1 \\ {r}_2=400\%=\frac{400}{100}=\frac{4}{1}=4 \\ b=3\text{cm} \\ b=r_2/r_1\cdot a \\ a=\frac{r_1}{r_2}\cdot b=\frac{1}{4}\cdot 3=\frac{1\cdot 3}{4}=\frac{3}{4}=0.75\text{cm} \end{gathered}$$

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