Question

Одна сеялка может засеять полеза 26 часов, другая- за 39,третья- за 52 часа. За сколько часов засеют это поле три сеялки, работая вместе?

Answer 1

Пусть все поле это 1. Тогда скорость первой сеялки 1/26; второй 1/39,третьей 1/52 поля в час. Когда работать будут вместе их скорости складываются: 1/26+1/39+1/52=6/156+4/156+3/156=13/156=1/12 поля в час -общая скорость.
Чтобы найти время надо все поле разделить на общую скорость:
1:1/12=12 часов им понадобится

Answer 2

Calculating the Time Taken by Three Seeders Working Together

To calculate the time taken by three seeders working together to sow a field, we can use the concept of "work done per unit time" to find the combined rate of work for all three seeders.

Let's denote: - The first seeder's rate of work as R1 (in fields per hour). - The second seeder's rate of work as R2 (in fields per hour). - The third seeder's rate of work as R3 (in fields per hour).

We can use the formula: Combined rate of work = R1 + R2 + R3

The time taken by the three seeders working together can then be calculated using the formula: Time = Total work / Combined rate of work

Calculations

Given: - The first seeder can sow the field in 26 hours. - The second seeder can sow the field in 39 hours. - The third seeder can sow the field in 52 hours.

Let's calculate the combined rate of work and the time taken by the three seeders working together.

The combined rate of work is: Combined rate of work = 1/26 + 1/39 + 1/52

Now, we can calculate the time taken by the three seeders working together: Time = 1 / (1/26 + 1/39 + 1/52)

Conclusion

By calculating the combined rate of work and using the formula for the time taken by multiple workers, we can determine the total time taken by three seeders working together to sow the field.