<human>:  A special school has a deaf-student population 3 times its blind-student population. If there are 180 students in total, how many blind students are there?
<bot>: Define a variable ** Let the number of blind students be x.
How many deaf students are there? ** The number of deaf students will then be 3*x = 3x students.
Write an equation ** The total number of students is x + 3x = 180 students.
Combine like terms ** Combining like terms gives 4x = 180.
Divide by 4 ** So the value of x is 180/4 = <<180/4=45>>45.
#### 45