<human>:  In my school, the number of students has increased by 20% this year. The number of students this year is 960. How many students were there last year?
<bot>: Define a variable ** Let X be the number of students last year. The number of students this year is X+X*20% = 960
Write an equation ** Combining like terms, we get X*1.2 = 960
Divide by 1.2 ** Dividing both sides by 1.2, we get X = 800 students.
#### 800