The store’s National Day promotion, the price of soda is changed from 6 yuan per 3 bottles to 6 yuan per 4 bottles, and yogurt is bought 1 bottle and free 1 bottle, Dongdonghua 42 yuan to buy several bottles of soda and yogurt at a preferential price, including soda The number of bottles is 4 less than three times the number of yogurt bottles. Dongdong found that this was 22 yuan cheaper than usual. Find the normal price of each bottle of yogurt.
商店国庆节促销，汽水的价格由每3瓶6元改为每4瓶6元，而酸奶则是买1瓶送1瓶，冬冬花42元按照优惠价购买汽水和酸奶若干瓶，其中汽水瓶数比酸奶瓶数的3倍少4，冬冬发现这比平时便宜了22元．求每瓶酸奶的正常价格．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<gadget id="calculator">42 - 30</gadget>
<output>12</output>

<gadget id="calculator">20 + 4</gadget>
<output>24</output>

<gadget id="calculator">24 / 3</gadget>
<output>8</output>

<gadget id="calculator">12 / 8</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>