For a rope, two fifths of the total length will be used for the first time, and the remaining two fifths will be used for the second time. There are still 180 meters left. How long is the rope originally?

For a rope, two fifths of the total length will be used for the first time, and the remaining two fifths will be used for the second time. There are still 180 meters left. How long is the rope originally?

180÷(1-2/5)÷(1-2/5)
=300÷3/5
=500 meters