Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
There are 30 students in the general study hall and twice as many students in the biology hall as there are in the general study hall. If the number of students in the math hall is 3/5 times as many as the combined total number of students in the general study hall and the biology hall combined,  calculate the total number of students in all the halls combined.

### Response:
In the biology hall, there are 30*2 = <<30*2=60>>60 students.
The total number of students in the general study hall and biology hall is 60+30 = <<60+30=90>>90 students.
The number of students in the maths hall is 3/5*90 = <<3/5*90=54>>54 students.
The total number of students in the three halls is 54+90 = <<54+90=144>>144 students
#### 144