Mom bought 3 bottles of shampoo and 1 bag of laundry detergent. Each bottle of shampoo was 6 yuan, and the total cost was 29 yuan. How much is a bag of laundry detergent?
妈妈买了3瓶洗发水和1袋洗衣液，每瓶洗发水6元，一共花了29元，一袋洗衣液多少钱？
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">29 - 18</gadget>
<output>11</output>

<result>11</result>