Please help me with the second, bolded part. Phosphorus-30, which has a half-life of 150 seconds, decays by positron emission. How long will it take

Please help me with the second, bolded part.

Phosphorus-30, which has a half-life of 150 seconds, decays by positron emission. How long will it take for 3.0% of this nuclide to decay? (Express your answer in seconds.)

=6.59 

How long will it take for 98.1% of this nuclide to decay? (Express your answer in seconds.)