Three packs of biscuits are twice as much as six packs bought in Yang Yang and 7 yuan (6÷3-2), so the price of three packs is doubled (7×2= 14).
Ask how much a * * * costs, and add the total price of yogurt and biscuits (15+ 14=29).
Such a ***29 yuan.
Dear ~ I'm glad to answer your question, I hope it will be adopted ~