Предмет: Математика, автор: proigravsihneostalos

4.В магазине побывало 65 человек.Известно что они купили 35 холодильников,36 микроволновок,37 телевизоров.20 из них купили и холодильник и микроволновку,19-и микроволновку и телевизор,15-холодильник и телевизор,а все три покупки совершили три человека.По условию задачи составьте диаграмму Эйлера Венна и ответьте на вопросы а) сколько посетителей магазина не купили не чего?
б) сколько человек купили только телевизоры

Ответы

Автор ответа: ahmadeevtimur20

Ответ:

Обозначим Холодильник Х, Телевизор Т, Микроволновку М.

Из 65 человек 3 купили сразу 3 покупки. Остальные 62 - меньше трёх.

Уменьшим все числа на 3, чтобы дальше не путаться.

Всего купили 32 Х, 33 М, 34 Т, 17 купили только Х и М, 16 купили только М и Т,

12 купили только Х и Т.

Значит, 32 - 17 - 12 = 3 купили только Х. 33 - 17 - 16 = 0 купили только М,

34 - 16 - 12 = 6 купили только Т.

Получается такая картина: 3 человека купили Х, М и Т. 17 купили Х и М.

16 купили М и Т. 12 купили Х и Т. 3 купили только Х, 6 купили только Т.

Никто не купил только М. Проверим.

Х купили: 3+17+12+3 = 35. М купили 3+17+16 = 36. Т купили 3+16+12+6 = 37.

Всё правильно. Всего купивших было:

3 + 17 + 16 + 12 + 3 + 6 = 57 человек. А всего пришло в магазин 65.

Значит, 65 - 57 = 8 человек не купили ничего.

Пошаговое объяснение:

Peterkalol: можно подробнее

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