Battery drainage - WiFi vs 3G

[Laban]

Hello!
I have the iPad 2 3G and I'm wondering about the drainage of the battery. Hope you can help me out.

1. If I have both 3G and WiFi activated at the same time I'm guessing that iPad is using the WiFi connection, right?

2. Does this also mean that it uses more battery (if 3G and WiFi is connected/activated at the same time).

3. What is using the least battery: 3G or WiFi?

Thanks in advance!

 

[refrainer]

when you turn both on, ipad will prefer wifi, then if no connection, it will be on 3g. if continuous usage, i find 3g drains faster than wifi, esp. if the signals aint that great.