Question

Решите пожалуйста задачу двумя способами!Лена может работать текст за 12 минут,а Света за 18 минут. Сколько времени понадобится Лене и Свете, чтобы выполнить всю работу, если они будут работать вместе?

Answer 1

1:12= 1/12 - Лена наберёт за минуту
2) 1:30=1/30- Света наберёт за минуту
3) 1/12+1/30=5/60+2/60=7/60- Наберут вместе за минуту
4) 7/60:60= 7/1:1=7 минут - понадобится чтобы набрать текст
Простите только так могу. Второй способ  не могу найти. Надеюсь помогла)

Answer 2

Problem Analysis

We are given that Lena can complete a task in 12 minutes and Svetlana can complete the same task in 18 minutes. We need to find out how much time it will take for both of them to complete the task if they work together.

Solution 1: Using the Formula

One way to solve this problem is by using the formula for the time it takes to complete a task when working together. The formula is:

Time taken when working together = (Time taken by person 1 * Time taken by person 2) / (Time taken by person 1 + Time taken by person 2)

Let's substitute the given values into the formula:

Time taken when working together = (12 * 18) / (12 + 18)

Simplifying the expression:

Time taken when working together = 216 / 30

Calculating the result:

Time taken when working together = 7.2 minutes

Therefore, it will take Lena and Svetlana approximately 7.2 minutes to complete the task if they work together.

Solution 2: Using the LCM

Another way to solve this problem is by finding the least common multiple (LCM) of the individual times taken by Lena and Svetlana. The LCM represents the smallest time interval in which both Lena and Svetlana will complete their respective tasks simultaneously.

The LCM of 12 and 18 can be found by prime factorizing the numbers:

12 = 2^2 * 3 18 = 2 * 3^2

Taking the highest power of each prime factor, we get:

LCM = 2^2 * 3^2 = 4 * 9 = 36

Therefore, it will take Lena and Svetlana approximately 36 minutes to complete the task if they work together.

Conclusion

To summarize, there are two ways to solve the problem. Using the formula, it will take Lena and Svetlana approximately 7.2 minutes to complete the task if they work together. Using the LCM, it will take them approximately 36 minutes to complete the task.