 
<translate> Da farko ka samu adadin koren duwatsu: 20 koren duwatsu / 2 = 10 koren duwatsu. Sa'an nan kuma gano yawan marbles ne ko dai ja ko blue: 60 marbles - 20 rawaya marbles - 10 kore marbles = 30 marbles. Raba wannan lambar a rabi don gano adadin marbles masu launin shuɗi: 30 marbles / 2 = 15 marbles masu launin shuɗi. A ƙarshe, raba adadin marbles na shuɗi ta yawan adadin marbles kuma ninka ta 100 don samun kashi na yiwuwar samun marble na shuɗi: 15 marbles / 60 marbles * 100 = 25%. Saboda haka, amsar ita ce 25. <eng> First find the number of green marbles: 20 yellow marbles / 2 = 10 green marbles. Then find how many marbles are either red or blue: 60 marbles - 20 yellow marbles - 10 green marbles = 30 marbles. Divide this number in half to find how many marbles are blue: 30 marbles / 2 = 15 blue marbles. Finally, divide the number of blue marbles by the total number of marbles and multiply by 100 to find the percentage chance of getting a blue marble: 15 marbles / 60 marbles * 100 = 25%.
Therefore, the answer is 25. 