Question

бригада трактористов может вспахать 5/6 участка земли за 4 часа 15 минут. До обеденного перерыва бригада работала 4,5 часа, после чего остались невспаханными ещё 7 га. Сколько га составляет весь участок?

Answer 1

4ч 15мин = 4 1/4 ч = 17/4 ч

4,5 ч = 9/2 ч

5/6 :17/4 = 10/51 участка  вспашет за 1 час

10/51 ·9/2 = 45/51 участка вспашет за 4,5 ч 

1 - 45/51 = 6/51 участка останется вспахать

6/51 составляет 7 га, 7 : 6/51 = 59,5 га 

Answer 2

Calculation of the Total Area

To calculate the total area of the land, we need to determine the area that the brigade of tractor drivers can plow in one hour.

Given that the brigade can plow 5/6 of the land in 4 hours and 15 minutes, we can calculate the plowing rate per hour as follows:

1. Convert the time to minutes: 4 hours and 15 minutes is equal to 255 minutes. 2. Calculate the plowing rate per minute: 5/6 of the land divided by 255 minutes. 3. Multiply the plowing rate per minute by 60 to get the plowing rate per hour.

Let's perform the calculations:

1. Convert the time to minutes: - 4 hours is equal to 4 * 60 = 240 minutes. - 15 minutes is equal to 15 minutes.

Therefore, the total time worked by the brigade before the lunch break is 240 + 15 = 255 minutes.

2. Calculate the plowing rate per minute: - The brigade can plow 5/6 of the land in 255 minutes. - Therefore, the plowing rate per minute is (5/6) / 255.

3. Calculate the plowing rate per hour: - Multiply the plowing rate per minute by 60 to get the plowing rate per hour.

Let's calculate the plowing rate per hour:

Plowing rate per minute = (5/6) / 255
Plowing rate per hour = Plowing rate per minute * 60

Calculation of the Remaining Unplowed Area

To calculate the remaining unplowed area after the lunch break, we need to determine the time worked after the lunch break and the area that remained unplowed.

Given that the brigade worked for 4.5 hours before the lunch break and there were still 7 hectares left unplowed, we can calculate the plowing rate per hour as follows:

1. Calculate the plowing rate per hour: - Divide the remaining unplowed area (7 hectares) by the time worked after the lunch break (4.5 hours).

Let's perform the calculation:

Plowing rate per hour = Remaining unplowed area / Time worked after lunch break

Calculation of the Total Area

To calculate the total area of the land, we need to add the remaining unplowed area to the area that the brigade can plow in one hour.

Given that the remaining unplowed area is 7 hectares and the plowing rate per hour is calculated as explained above, we can calculate the total area as follows:

1. Calculate the total area: - Multiply the plowing rate per hour by the total time worked by the brigade, including the time before the lunch break and after the lunch break. - Add the remaining unplowed area to the calculated area.

Let's perform the calculation:

Total area = (Plowing rate per hour * Total time worked) + Remaining unplowed area

Now, let's calculate the total area using the given information.