Problem K/C. 748. (December 2022)

K/C. 748. The integers 1 to 100 are written along the circumference of a circle. First every even number is connected to each odd number that is smaller than the even number. Then every odd number is connected to each even number that is smaller than the odd number. How many connecting lines are drawn?

(5 pont)

Deadline expired on January 10, 2023.

Sorry, the solution is available only in Hungarian. Google translation

Megoldás. Minden páratlan számot összekötünk először a nála nagyobb, majd azután a nála kisebb páros számokkal is. Más vonalat nem húzunk be. 1-től 100-ig 50 páratlan szám van és 50 páros, így \(\displaystyle 50\cdot50=2500\) vonalat húzunk be.

Statistics:

292 students sent a solution.
5 points:	207 students.
4 points:	30 students.
3 points:	10 students.
2 points:	3 students.
1 point:	3 students.
0 point:	7 students.
Unfair, not evaluated:	21 solutionss.
Not shown because of missing birth date or parental permission:	7 solutions.

Problems in Mathematics of KöMaL, December 2022