I have a Magento 1.9 installation. and in it I have grouped virtual simple products and it works very well. In the grouping I have two products, and I would like that in the shopping cart when choosing the grouped product the first and second product of the group have the same amount. For example, if I have the quantity of 2 products in the first one, the second one is the same (2). and that the second one cannot be changed.