*해설

<문제 해설>
감소하는황 = (1-(나중황/처음황)) X 100
= (1-(400kl(0.05 x 0.5 + 0.01 x 0.5))/(400kl x 0.05)) X 100
[해설작성자 : jk]

효율 = (1 - Co/Ci) * 100
= (1- ((0.05*200)+(0.01*200)/(0.05*400)) * 100
= 40%