Question

甲乙两队合作修一条公路,如果单独修甲要20天,乙要30天,现在两队合修到完工时甲队比乙队多修360m,

Answer 1

1/(1/20+1/30)

=12天

12*(1/20-1/30)

=12*1/60

=1/5

360/1/5

=360*5

=1800m