Question

На заседании присутствует 29 академиков. 12 из них имеют бороду, а 18 усы! у трёх академиков нет ни бороды ни усов! сколько академиков имеют и бороды и усы?

Answer 1

29-3=26
|26-(18+12)|=4
ответ : 4 имеют и усы и бороду

Answer 2

Problem Analysis

We are given that there are 29 academicians present at a meeting. Out of these, 12 have beards and 18 have mustaches. Additionally, there are three academicians who have neither beards nor mustaches. We need to determine how many academicians have both beards and mustaches.

Solution

Let's break down the information given: - Total number of academicians: 29 - Number of academicians with beards: 12 - Number of academicians with mustaches: 18 - Number of academicians with neither beards nor mustaches: 3

To find the number of academicians with both beards and mustaches, we can use the principle of inclusion-exclusion. We'll start by adding the number of academicians with beards and the number of academicians with mustaches, and then subtract the number of academicians with neither beards nor mustaches.

Number of academicians with both beards and mustaches = (Number of academicians with beards) + (Number of academicians with mustaches) - (Number of academicians with neither beards nor mustaches)

Let's substitute the given values into the equation:

Number of academicians with both beards and mustaches = 12 + 18 - 3 = 27

Therefore, there are 27 academicians who have both beards and mustaches.

Answer

There are 27 academicians who have both beards and mustaches.