The weight of soda was 6*12=<<6*12=72>>72 ounces
It had to support the weight of 6+2=<<6+2=8>>8 empty cans
The weight of the empty cans is 8*2=<<8*2=16>>16 ounces
So it must support 72+16=<<72+16=88>>88 ounces
#### 88