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

### Instruction:
Oleg is an event organizer. He is organizing an event with 80 guests where 40 of them are men, half the number of men are women, and the rest are children. If he added 10 children to the guest list, how many children will there be at the event?

### Response:
Since there are 40 men, then there are 40/2 = <<40/2=20>>20 women.
So, the total number of men and women at the event is 40 + 20 = <<40+20=60>>60.
Hence, there are 80 - 60 = <<80-60=20>>20 children.
After Oleg added 10 children to the guest list, the total number of children became 20 + 10 = <<20+10=30>>30.
#### 30