The animal shelter is building cages for 26 dogs and 34 cats.
26 + 34 = 60
It needs to build 60 cages.
The first crew builds 1 cage in 1 hour. Rate: 1 cage/hour
The second crew builds 1 cage in 2 hours, or 1/2 cage in 1 hour. Rate: 1/2 cage/hour
They work together for x hours and build all 60 cages.
In x hours, the first crew builds 1 cage/hour * x hours = x cages.
In x hours, the second crew builds 1/2 cage/hour * x hours = 1/2 x cages.
Combined, they build 60 cages.
x + 1/2 x = 60
x + 0.5x = 60
1.5x = 60
x = 40
Answer: It will take 40 hours.
Check: In 40 hours, the first crew builds 40 cages.
In 40 hours, the second crew builds 20 cages.
40 + 20 = 60
In 40 hours, the two crews build 60 cages.
Our answer above is correct.
