•Volume of model 1: 16^3 [ + ] 20^3 because in order to get the entire volume you would need to combine the 2 separate parts. •Volume of Green Model in Model 2: it would be [ 12 ] because if the models are equivalent in volume you would get the equation 16+20=24+x. 36=24+x Addition. 12=x= green model Subtraction. Hope this helps and if needed, use as a reference in the future :)