The motor ship passed 2/5 of the distance AB. Find AB if there is still 13 km 100 m left before halfway.

To solve this task, remember, in order to find the number by its part, expressed as a fraction, you need to divide this number by a fraction. Let’s convert kilometers to meters. 1 km = 1000 meters. 13 km 100 m = 13 * 1000 + 100 = 13100 m. Let us calculate how much of the path is left to go to half.
1/2 – 2/5 = 5 – 4 = 1/10.
Knowing that 1/10 of the entire path is 13100 meters, we calculate what the distance is equal to.
13100: 1/10 = 13100 * 10 = 131000 meters.
Answer: 131,000 meters.