Question

Две бригады выполняют задание за 14 дней. За сколько дней выполняет задание 1я бригада если 2я бригада одна может выполнить задание за 21 день

Answer 1

Ответ:

Пошаговое объяснение:

1) 1 : 14 = 1/14 задания - выполняет 1ая бригада за 1 ч

2) 1 : 10 = 1/10 задания - выполняют обе бригады вместе

3) 1/10 - 1/14 = 7/70 - 5/70 = 2/70 = 1/35 задания - выполняет 2ая за 1ч

4) 1 : 1/35 = 1 * 35 = 35 ч - вторая бригада может выполнить задание.

Answer 2

To solve this problem, we can use the concept of work done. Let's assume that the amount of work required to complete the task is represented by "W."

Given that two brigades together can complete the task in 14 days, we can express their combined work rate as follows:

Work rate of 1st brigade + Work rate of 2nd brigade = 1 job / 14 days

Now, we are told that the 2nd brigade can complete the task on its own in 21 days. Therefore, the work rate of the 2nd brigade alone is:

Work rate of 2nd brigade = 1 job / 21 days

Next, let's find the work rate of the 1st brigade, which is represented by "x" (jobs per day):

Work rate of 1st brigade + 1 job / 21 days = 1 job / 14 days

Now, we can solve for the work rate of the 1st brigade:

Work rate of 1st brigade = 1 job / 14 days - 1 job / 21 days

To combine the fractions, we need to find a common denominator, which is the least common multiple (LCM) of 14 and 21, which is 42. Now we can rewrite the equation:

Work rate of 1st brigade = (3 / 42) - (2 / 42) = 1 / 42

So, the work rate of the 1st brigade is 1 job every 42 days.

Finally, to find out how many days the 1st brigade can complete the task alone, we can calculate the reciprocal of their work rate:

Number of days for 1st brigade to complete the task alone = 1 / (1 / 42) = 42 days

Thus, the 1st brigade can complete the task on its own in 42 days.