Peter and John have a picnic.Peter eats half of the cakes,then John eats half of the remaining cakes plus three more.There are no cakes left.How many cakes do they take to picnic?
问题描述：
Peter and John have a picnic.Peter eats half of the cakes,then John eats half of the remaining cakes plus three more.There are no cakes left.How many cakes do they take to picnic?
答
twelve
根据题意可得算式：1/2 x=1/2*1/2x+3
解得x=12