Hey there!
Here is your answer:
They proper answer to this question is "72 hours".
Reason:
By using the ratio:
[tex] \frac{3days}{hours} [/tex]
You can see that one day = 24 hours
[tex] \frac{1day}{24hours} [/tex]
Then multiply 24×3=72
[tex] \frac{3days}{72hours} [/tex]
Therefore the ratio is [tex] \frac{3days}{72hours} [/tex]!
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit