The tourist walked on the first day 12 km, which is 15% of the entire path, determine the entire path of the tourist.

Let’s calculate the entire mileage of the tourist’s path. To do this, we make up the proportion and, express in n kilometers the entire path of the tourist, as well as equating this entire path to 100%:
12 km – 15%,
n – 100%.
Now an equation is drawn up from the initial data and solved:
n = 12 km * 100%: 15%;
n = 1200: 15;
n = 80 kilometers – makes up the entire path of the tourist.
Answer: the entire travel of a tourist is 80 kilometers.