Answer:
2/5
Explanation:
To get the ratio as a pure number, it must be expressed as the quotient of two values that have the same units. For the purpose here, it is convenient to convert both values to units of seconds.
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units conversion
The conversion factor between minutes and seconds is ...
1 minute = 60 seconds
Multiplying this equation by 3 gives ...
3 minutes = 180 seconds
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ratio of interest
Then the desired ratio is ...
(72 seconds)/(3 minutes) = (72 seconds)/(180 seconds) = 72/180
= (36×2)/(36×5)
= 2/5
The ratio in its simplest form is 2/5.