<human>:  The number of short students in a class is 2/5 of the total number of students. If there are 90 tall students, and the class has 400 students, calculate the total number of students with average height.
<bot>: How many short students are there? ** The number of short students in the class is 2/5*400 = <<2/5*400=160>>160
How many students are there? ** The total number of short and tall students is 160+90 = <<160+90=250>>250
How many students are there with average height? ** Since there are 400 students in the class, the number of students with average height is 400-250 = <<400-250=150>>150
#### 150