OG13数学21和DT6题目的意思

puzzledog

求大牛帮我翻译题意，红色部分是不明白的类容，谢谢了
21 John deposited $10.000 to open a new savings account that earned 4 percent annual interest, compounded quarterly.

DT6 A market firm determined that , of 200 households surveyed .80 used Brand A nor Brand B soap, 60 used only Brand A soap, and for every household that used both Brands of soap, 3 used only Brand B soap.

看了OG的解释才知道用B牌子的人是用AB牌子人数的3倍。要是自己看的话不会明白题目的意思，这句话是不是说对于每一个用A和B牌子的人，3个人用B牌子？能不能翻译个准确的意思？

SDty8

第一题就是复利4%
要记住复利的计算公式（1+4%）^n*本金。此题是4%
第二题 用画图集合的方法，这是考试最常见的一种题。意思是每个选择两个牌子的人，会有3倍的人选b这种表达要记住。

puzzledog

John deposited $10.000 to open a new savings account that earned 4 percent annual interest, compounded quarterly.If there  were no other transctions in the account, waht was the amo mount of mount of money in John'S account 6 months after the account was opened?

我知道是复利，关键是后面的QUARTERLY。解释说得是这样话的话每3个月的利息就是1%，这样结果就是10000X1.01X1.01.前面说年率是4%，后面的COMPOUNDED QUARTRTLY就是说按季度复利？
谢谢解答了，第2问我想应该就是我不熟悉的表达方式吧，会记住的