Question

甲、乙两人共同加工一批机器零件,9天正好加工了这批零件悳30%,这时,甲比乙多加工叻72个,如果甲单独做这批零件40天完

Answer 1

30%/9=1/30

(1/30)-(1/40)=1/120

(9/40)-(9/120)=3/20

3/20x=72

x=480