Question

Двое учеников очистили 400 картофелин. Один очищал в минуту 3 штуки, а дугой-2. Второй работал на 25 минут больше первого. сколько времени работал каждый?

Answer 1

В 1 минуту вместе чистят вместе 5 картофелин .
400:5= 80 минут
х+(25+х)=80
2х=80-25
х=55
один работал 27мин 30 сек
второй + 25 мин = 52 мин 30 сек

Answer 2

Problem Analysis

Two students are cleaning 400 potatoes. One student can clean 3 potatoes per minute, while the other can clean 2 potatoes per minute. The second student works for 25 minutes longer than the first student. We need to determine how long each student worked.

Solution

Let's assume the first student worked for x minutes. Since the second student worked for 25 minutes longer, the second student worked for x + 25 minutes.

The total number of potatoes cleaned by the first student is 3x, and the total number of potatoes cleaned by the second student is 2(x + 25).

According to the problem statement, the sum of the potatoes cleaned by both students is 400. Therefore, we can set up the following equation:

3x + 2(x + 25) = 400

Now, let's solve this equation to find the values of x and x + 25.

Calculation

Expanding the equation: 3x + 2x + 50 = 400

Combining like terms: 5x + 50 = 400

Subtracting 50 from both sides: 5x = 350

Dividing both sides by 5: x = 70

Therefore, the first student worked for 70 minutes, and the second student worked for 70 + 25 = 95 minutes.

Answer

The first student worked for 70 minutes, and the second student worked for 95 minutes.