Answer:
2/7
Explanation:
They traveled 2/5 of the remaining distance which is 5/7. So you need 2/5 of 5/7.
When you see the word 'of' just know that it generally means multiply. To know what 2/5 of 5/7 is, you need to multiply them together, which results in 2/7.
This makes sense because if I told you to calulate 2/3 of a meter, you would divide a meter into 3 to find one thirds of a meter, then you would multiply that by 2 since you need two thirds. Same thing here. divide 5/7 by 5 to get 1/7. Multiply that by 2 since you need 2 fifths, to get 2/7.