甲捐款是四个人的:1÷(1+3) =1/4乙捐款是四个人的:1÷(1+5) =1/6丙捐款是四个人的:1÷(1+6) =1/7四人总捐款数:148÷(1-1/4-1/6-1/7) =148÷(1-47/84) =148÷37/84 =148×84/37 =4×84 =336元乙捐款:336×1/6 =56元