Question

первая бригада может выполнить работу за 3 целых 2/5 часа а вторая бригада на 3/4 часа медленнее за сколько часов могут выполнить роботу обе бригады работая вместе ​

Answer 1

Ответ:

3 31/40

Пошаговое объяснение:

1бр- 3 2/5

2бр- 3 2/5+3/4

3 2/5+3/4- привести к общему знаменателю 20

3 8/20+15/20= 3 23/20= 4 3/20 затратит время вторая бригада

3 2/5+ 4 3/20- привести к общему знаменателю 20

3 8/20+4 3/20= 7 11/20 общее время на работу, т.к бригады 2, то

7 11/20:2= 7 11/20×1/2= 3 31/40 время затраченное на работу двумя бригадами

Answer 2

Calculation of Work Efficiency

To determine how long it would take for both brigades to complete the work together, we need to calculate their individual work efficiencies based on the given information.

Let's assume that the first brigade's work efficiency is represented by x (in units of work per hour). Since the first brigade can complete the work in 3 and 2/5 hours, we can express their work efficiency as:

x = 1 / (3 + 2/5) = 1 / (17/5) = 5/17.

Similarly, let's assume that the second brigade's work efficiency is represented by y (in units of work per hour). Since the second brigade is 3/4 hours slower than the first brigade, we can express their work efficiency as:

y = 1 / (3 + 2/5 + 3/4) = 1 / (17/5 + 3/4) = 1 / (68/20 + 15/20) = 1 / (83/20) = 20/83.

Calculation of Combined Work Efficiency

To calculate the combined work efficiency of both brigades working together, we can add their individual work efficiencies:

Combined Work Efficiency = x + y = 5/17 + 20/83.

To simplify this expression, we need to find a common denominator:

Combined Work Efficiency = (5/17) * (83/83) + (20/83) * (17/17) = 415/1411 + 340/1411 = 755/1411.

Therefore, the combined work efficiency of both brigades working together is 755/1411.

Calculation of Time Required for Both Brigades to Complete the Work

To calculate the time required for both brigades to complete the work together, we can use the formula:

Time = Total Work / Combined Work Efficiency.

Since the total work is the same for both brigades, we can assume it to be 1 unit.

Time = 1 / (755/1411) = 1411/755.

Therefore, both brigades working together can complete the work in approximately 1.868 hours.

Please note that the calculations provided are based on the given information and assumptions made.