So imagine you're working in the customer service call centre for, say, Sony. Someone rings up saying the remote for his television is not working. You ask him to press a button on the remote which, if the remote works, will make the remote light up. He says it does not light up when he presses that button.
What's the best way of finding out whether he has placed batteries in the remote control without directly asking him and risking his thinking that you are calling him a fool? A prize is available for the best response.