#### Answer

The total text messages Miriam sent that month is 1285.

#### Work Step by Step

10 dollars for the first 1000 text messages and 10 cents for each additional text message, Miriam’s bill for text messages for the month of June is 38.50 dollars, so she has more than 1000 text messages.
Let x be the amount of additional text messages, we have: $\frac{10}{100} \times x = 38.50 - 10=28.50$
$0.1x=28.50$, So $x=285$ messages
The total text messages Miriam sent that month is $1000+285=1285$.