Question

Дикая утка от южного мопя до северного моря долетит за 7 дней.дикий гусь от северного моря до южного долетит за 9 дней.через сколько они встретятся если вылетЯт одновременно?

Answer 1

1:7=1/7(часть)
1:9=1/9(часть)
1/7+1/9=16/63(часть)
1:16/63=63/16=3целых15/16(дней)
Ответ:3целых15/16 дней птицы встретятся

Answer 2

Problem Analysis

We are given that a wild duck can fly from the southern sea to the northern sea in 7 days, and a wild goose can fly from the northern sea to the southern sea in 9 days. We need to determine how many days it will take for them to meet if they start flying at the same time.

Solution

Let's assume that the distance between the southern sea and the northern sea is the same for both the duck and the goose. We can represent this distance as d.

Since the duck can cover this distance in 7 days, its speed can be calculated as d/7 units per day.

Similarly, the goose can cover the same distance in 9 days, so its speed can be calculated as d/9 units per day.

If both the duck and the goose start flying at the same time, they will meet when the sum of the distances covered by each of them is equal to the total distance between the seas.

Let's assume that they meet after t days. The distance covered by the duck in t days can be calculated as (d/7) * t, and the distance covered by the goose in t days can be calculated as (d/9) * t.

According to the problem, the sum of these distances should be equal to d:

(d/7) * t + (d/9) * t = d

We can simplify this equation by multiplying both sides by 63 (the least common multiple of 7 and 9) to eliminate the denominators:

9t + 7t = 63

Simplifying further:

16t = 63

Solving for t:

t = 63/16

Therefore, they will meet after approximately 3.9375 days.

Answer

If the wild duck and the wild goose start flying at the same time, they will meet after approximately 3.9375 days.