Question

826. в стране 18 больших городов, каждые два из которых соединены авиалинеей. Сколько всего авиалений между городами.

Answer 1

1. 18*17=306 (рейсов)
2. 306:2=153 (линии) - ответ.

Answer 2

18*17=306 это рейсов но мы делим на два чтобы получить линии 306:2=153 (линий).

Answer 3

Total Number of Flights Between Cities in the Country

In a country with 18 major cities, each pair of cities is connected by an airline. To calculate the total number of flights between the cities, we can use the combination formula, which is nCr = n! / (r! * (n-r)!), where n is the total number of items and r is the number of items to choose.

Using this formula, we can calculate the total number of flights as follows:

Total number of flights = 18C2

Substituting the values into the combination formula: 18C2 = 18! / (2! * (18-2)!)

Calculating: 18C2 = 18! / (2! * 16!) = (18 * 17) / 2 = 153

Therefore, there are a total of 153 flights between the 18 major cities in the country.