Question

Три бригады строителей должны построить 2 одинаковых дома. На строительство одного дома первой бригаде потребуется 9 недель, второй бригаде -- в 1 1-3 (одну целую одну третью) раза больше времени, а третьей бригаде -- в 2 раза больше времени, чем первой. За сколько недель три бригады построят два дома, работая совместно?

Answer 1

1)9•1 1/3=12
2)9•2=18
3)12+18+9=39

Answer 2

Calculating Construction Time for Two Identical Houses by Three Brigades

To calculate the time it will take for three brigades to build two identical houses, we can use the given information about the time each brigade takes to build one house.

- The first brigade takes 9 weeks to build one house. - The second brigade takes 11 1/3 (or 34/3) times longer than the first brigade to build one house. - The third brigade takes 2 times longer than the first brigade to build one house.

Let's calculate the total time it will take for the three brigades to build two houses working together.

Calculations

To find the total time, we can use the concept of "man-weeks," which is the amount of work done by one person in one week.

- The first brigade's time to build one house is 9 weeks, so their man-weeks for one house is 1 * 9 = 9. - The second brigade's time to build one house is 34/3 times longer than the first brigade, so their man-weeks for one house is (34/3) * 9. - The third brigade's time to build one house is 2 times longer than the first brigade, so their man-weeks for one house is 2 * 9.

Now, we can calculate the total man-weeks required to build two houses by adding the man-weeks for each brigade for one house and then multiplying by 2 for two houses.

Total Man-Weeks for Two Houses

- For the first brigade: 9 * 2 = 18 man-weeks for two houses. - For the second brigade: (34/3) * 9 * 2 = 204/3 = 68 man-weeks for two houses. - For the third brigade: 2 * 9 * 2 = 36 man-weeks for two houses.

Adding these together, the total man-weeks for two houses by all three brigades is 18 + 68 + 36 = 122.

Therefore, it will take the three brigades a total of 122 weeks to build two identical houses working together.

Final Answer

It will take the three brigades a total of 122 weeks to build two identical houses working together.