Working together, four pugs can clean their house in 45 minutes. In how many minutes will 15 pugs working together be able to clean their house?
Stream of thoughts:
12
If four pugs can clean their house in 45 minutes, one pug will take 4 * 45 = 180 minutes.

Since one pug working alone takes 180 minutes to clean the house, fifteen pugs working together will be able to clean their house in 180 / 15 = 12 minutes.

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The answer is 12