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

### Instruction:
Robert had 25 balls. Tim gave him half of his 40 balls. How many balls does Robert have now?

### Response:
Tim gave 1/2 * 40 balls = 20 balls to Robert.
Now Robert has 25 + 20 = <<25+20=45>>45 balls.
#### 45