What is the half-life of a compound if 75 percent of a given sample of the compound decomposes in 60 min? assume first-order kinetics?

The amount left of a given substance can be calculated through the equation,
                                              A = (A0) x 0.5^n/h
From the given scenario, 
                                           A/A0 = 0.75 = 0.5*(60/h)
The value of h from the equation is 144.565 minutes. 

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