$~N~$ students come per $~0.5~$ hours( in $~30~$ minutes)in average and how many average in students come per hour?

Question

I've been doing the assignment of operations research .

The one copier (copy machine ) exists and we assume that student are making a queue to use the copier .

Students follow Poisson distribution and 5 students come in average per 30 minutes .

Then how many students come per hour?

I've thought that just simply multiplying it by 2 and have got 10 students per hour .

But I think it is wrong .

Can anyone give me what website should I refer?