Question

На трёх деревьях сидели 45 скворцов. Когда с первого дерева улетели 5 скворцов, со второго - 7, а на третий прилетели 3, то на всех трёх деревьях стало скворцов поровну. Сколько скворцов сидело первоначально на третьем дереве?

Answer 1

9 скворцов сидело первоначально на третьем дереве

Answer 2

Problem Analysis

We are given that there were 45 sparrows sitting on three trees. When 5 sparrows flew away from the first tree, 7 flew away from the second tree, and 3 flew to the third tree, the number of sparrows became equal on all three trees. We need to determine the initial number of sparrows on the third tree.

Solution

Let's assume that the initial number of sparrows on the third tree was x.

According to the given information, the number of sparrows on the first tree decreased by 5, the number on the second tree decreased by 7, and the number on the third tree increased by 3. After these changes, the number of sparrows became equal on all three trees.

So, we can set up the following equation:

x - 5 = (45 - x) - 7 + 3

Simplifying the equation:

x - 5 = 45 - x - 4

Combining like terms:

2x = 36

Solving for x:

x = 18

Therefore, the initial number of sparrows on the third tree was 18.

Answer

The initial number of sparrows on the third tree was 18.