Answer:
2/7
Explanation:
travelled 2/7 of the distance on saturday.
that leaves 5/7 of the journey still to go.
they travelled 2/5 of the remaining distance on sunday.
that is, they travelled 2/5 of 5/7 on sunday.
2/5 X 5/7 = 2/7.
7/7 is the whole journey. so they travelled (2/7) / (7/7) = 2/7 of the total distance on sunday.
see attachment