Question

Один тракторист мог бы вспахать поле за 10 часов,а другой(его ученик)-за 40 часов.За сколько часов вспашут поле два тракториста при совместной работе?

Answer 1

Всё поле -1.
1/10 часть поля вспашет тракторист за 1 час
1/40 -ученик за 1 час
1/10+1/40=4/40+1/40=5/40=1/8 часть поля,которую за 1 час они вспашут вместе

1: (1/8)= 8 часов -за столько часов они вспашут поле,работая вместе

Ответ: за 8 часов.

Answer 2

Problem Analysis

To solve this problem, we can use the concept of "work done" and "work rates". The work rate of a person is the amount of work they can do in a unit of time. In this case, the work rate of the first tractor driver is 1 field per 10 hours, and the work rate of the second tractor driver is 1 field per 40 hours.

Solution

To find out how long it will take for both tractor drivers to plow the field together, we can use the formula: Total work = Work rate of person 1 * Time + Work rate of person 2 * Time

Let's calculate the time it will take for both tractor drivers to plow the field together.

Calculation

Using the given work rates: - Work rate of the first tractor driver = 1 field per 10 hours - Work rate of the second tractor driver = 1 field per 40 hours

Let's denote the time it takes for both tractor drivers to plow the field together as T.

According to the formula: Total work = Work rate of person 1 * T + Work rate of person 2 * T

Substituting the given work rates: 1 * T + 1 * T = 1

Solving for T: 2T = 1 T = 1/2

Answer

So, it will take both tractor drivers 0.5 hours to plow the field together.