Can I change Advert1 - 4 position in HOTfurniture?

I want to place some content in the Advert positions an there are 4. I understand that if I only use two positions, the content will use 50% of the space each, If I use 3, it adjusts to 33% each.
BUT
I would like one lot of content to take up one third of the space and the other one to take up the remaining two thirds.
I tried placing content in Advert 1 and Advert 2 and create some blank content for Advert4 but it is not doing what I had hoped.
Is there some way I can force the content from Advert 2 to take up the remaining third of the space available?

Thanks for any advice
Viv

ID of Adverts 1-4 containers are #a1,#a2,#a3,#a4 so you can add in layout.css width overrides:

#a1{
width:49%!important;
}

#a2{
width:24%!important;
}

#a3{
width:24%!important;
}

#a4{
display:none!important;
}

Thanks for that but it didn't work because the containing div class "modulerow2" had already had width set earlier as 49.7%.
The modulerow class is used in the footer as well so altering it or disabling it would throw out the footer modules.
I managed to get what I wanted using this:

#a1 {
float: left;
width:300px!important;
margin: 0;
}


#a2 {
float: right;
width:600px!important;
margin-right: 10px;

}

seems to work.
thanks