Given:
The ratio of the number of text messages sent by Tiffany to the number of text messages sent by her brother is 3 to 4.
Tiffany sent 12 text messages.
Let the number of messages of her brother = x
So,
[tex]\begin{gathered} 3\colon4=12\colon x \\ \\ \frac{3}{4}=\frac{12}{x} \end{gathered}[/tex]solve for x:
So, x = ( 4 * 12 )/3 = 16
So, the answer will be the number of messages of her brother = 16
