IOM 2016, Блиц — Задача 78
Olympiad of Metropolises, Moscow. Blitz Contest, September, 5 · 5 септември 2016 г.
Условие
The average score in a class on an exam is 70.
The average of students who scored below 60 is 50.
The average of students who scored 60 or more is 75.
If the total number of students in this class is 20, how many students scored below 60?
Решение
Внимание: Непълно решение
В архива няма официално решение на тази задача.
Оригинал в Архива: blitz.pdf