Okay, here we have this:
Considering the provided information, we are going to calculate how many messages did they each send, so let's solve the following equation (where x represents the number of messages sent by Josh):
[tex]\begin{gathered} 4x+(10+x)+x=160 \\ 6x+10=160 \\ 6x=150 \\ x=\frac{150}{6} \\ x=25 \end{gathered}[/tex]Then, we have that:
Number of text messages Chang sent= 4x= 4*25=100
Number of text messages Martina sent= 10+x = 10 + 25 = 35
Number of text messages Josh sent= x= 25
