The first volume of mathematical problems in the sixth grade of primary school 20 16 A road is 60 kilometers long, and the ratio of the distances of three mountain sections is one to two to three, and the mold core has been finished.
1, length of each segment: from 1+2+3=6,
Uphill 60x 1/6= 10km, flat road 60x2/6=20km, downhill 60x3/6=30km.
2. Time period: from 4+5+6= 15,
Uphill 10 ÷ 3 = 10/3h, flat road 10/3x5/4 = 12.5/3h, downhill 10/3x6/4 = 5h.
The total * * * time is10/3+12.5/3+5 =12.5 hours.