Farmers who have formulated a dairy cow insurance policy in a certain place and implemented standardized breeding of dairy cows. The insurance premium for the cow is 200 yuan. (3/10), (1/5) and (1/2) are borne by districts, townships and farmers respectively. How much does the farmer need to invest in insurance for each cow?
某地制定了奶牛保险政策，实施标准化饲养奶牛的农户．奶牛的保险费为200元．由区、乡镇和农户分别承担其中的(3/10)、(1/5)和(1/2)．农户需为每头奶牛投入多少元的保险费？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">200 * (1/2)</gadget>
<output>100</output>

<result>100</result>