Question

Учитель 0,4 урока объяснял новый материал, 5/9 ( простая дробь) остального времени урока ушло на решение задач, а в оставшиеся время учащиеся писали сам. работу. сколько минут учащиеся писали самостоятельную работу, если урок длится 45 минут?

Answer 1

0,4 * 45 = 18 минут ушло на объяснение нового материала

45 - 18 = 27 минут урока осталось

27 * 5/9 = 15 минут ушло на решение задач

27 - 15 = 12 минут писали самостоятельную работу

 

 

Answer 2

Problem Analysis

In this problem, the teacher spent 0.4 of the lesson explaining new material, and the remaining time was divided between solving problems and students working on their own. We need to determine how many minutes the students spent working on their own if the lesson lasted 45 minutes.

Solution

To find the number of minutes the students spent working on their own, we need to subtract the time spent on explaining new material and solving problems from the total lesson time.

Given: - Lesson duration: 45 minutes - Time spent explaining new material: 0.4 * 45 minutes - Time spent solving problems: (5/9) * (45 - (0.4 * 45)) minutes

To find the time spent by students on their own, we subtract the time spent explaining new material and solving problems from the total lesson time:

Time spent by students on their own = Total lesson time - Time spent explaining new material - Time spent solving problems

Let's calculate the solution step by step:

1. Calculate the time spent explaining new material: - Time spent explaining new material = 0.4 * 45 minutes

2. Calculate the time spent solving problems: - Time spent solving problems = (5/9) * (45 - (0.4 * 45)) minutes

3. Calculate the time spent by students on their own: - Time spent by students on their own = 45 minutes - (time spent explaining new material) - (time spent solving problems)

Let's calculate the solution:

1. Calculate the time spent explaining new material: - Time spent explaining new material = 0.4 * 45 minutes = 18 minutes

2. Calculate the time spent solving problems: - Time spent solving problems = (5/9) * (45 - (0.4 * 45)) minutes - Time spent solving problems = (5/9) * (45 - 18) minutes - Time spent solving problems = (5/9) * 27 minutes - Time spent solving problems ≈ 15 minutes

3. Calculate the time spent by students on their own: - Time spent by students on their own = 45 minutes - (time spent explaining new material) - (time spent solving problems) - Time spent by students on their own = 45 minutes - 18 minutes - 15 minutes - Time spent by students on their own ≈ 12 minutes

Therefore, the students spent approximately 12 minutes working on their own during the lesson.

Answer

The students spent approximately 12 minutes working on their own during the 45-minute lesson.