Question

Мастер за дом 30 дней, а второй за 45 дней построить дом. За сколько они вместе закончится дом.

Answer 1

(1/30+1/45)х=1
(3/90+2/90)х=1
5/90 х=1
1/18 х =1
х=18

Answer 2

Calculation of Construction Time

To calculate the total time it will take for two builders to complete a house, we need to know the individual construction times for each builder. According to the information provided, the first builder can complete the house in 30 days, while the second builder can complete it in 45 days.

To find the total time it will take for both builders to finish the house together, we can use the concept of work rates. The work rate is the amount of work done per unit of time. In this case, we can assume that the work rate is constant for each builder.

Let's calculate the work rates for each builder:

- The first builder can complete the house in 30 days, so their work rate is 1 house / 30 days. - The second builder can complete the house in 45 days, so their work rate is 1 house / 45 days.

To find the combined work rate of both builders, we can add their individual work rates:

Combined work rate = Work rate of the first builder + Work rate of the second builder

Combined work rate = 1 house / 30 days + 1 house / 45 days

To simplify the calculation, we can find a common denominator for the two fractions:

Combined work rate = (45 / 45) * (1 house / 30 days) + (30 / 30) * (1 house / 45 days)

Combined work rate = (45 / 1350) + (30 / 1350) houses per day

Combined work rate = 75 / 1350 houses per day

Simplifying further, we get:

Combined work rate = 1 / 18 houses per day

Now that we have the combined work rate, we can calculate the total time it will take for both builders to finish the house by dividing the total work (1 house) by the combined work rate:

Total time = Total work / Combined work rate

Total time = 1 house / (1 / 18 houses per day)

Simplifying, we get:

Total time = 18 days

Therefore, it will take both builders together a total of 18 days to complete the house.