16 sparrows were resting on 2 lamp post
2 sparrow flew from the first to the second lamp post
3 sparrows flew from the second to the first lamp posts .
The number of sparrows on the first and the second lamp posts became the same.
How many sparrows on each lamp post at first.
giúp mik thêm bài này zới:
There are 30 days in the month of April.31 students will be celebrating their birthdays in that month
Can you find 2 student who were born on the same day? Why?
cảm ơn các bn rất nhiều, các bn làm đc bài nào thì chỉ mik zới nhé
Bài 1: First task:
Let \(x\) be the number of sparrows on the first lamp post at first. (\(x\) is a positive integer).
\(\Rightarrow16-x\)is the number of sparrows on the second lamp post at first.
We have: \(x-2+3=16-x+2-3\Leftrightarrow2x=14\Leftrightarrow x=7\)
Hence there are 7 sparrows on the first lamp post at first, 9 sparrows on the second lamp post at first.
Bài 2: Second Task
We can find 2 students who were born on the same day.
There are 30 days in April and 31 students were born on that month. Apply the Dirichlet 's theorem, we can ensure that threre exists at least one day where 2 students were born.
