Question

一辆快车每小时行60千米,一辆慢车每小时行45千米,从甲地开往乙地.快车行完全程需15小时,

Answer 1

15*(60-45)÷45

=15*15÷45

=5小时

15*60÷45-15

=900÷45-15

=20-15

=5小时