Answer:

Step-by-step explanation:
The half life is the amount of time it takes a substance to decay to half of its original amount.
Since the radioactive substance has a half life of 1000 years, there will be half of it left after 1000 years.
So, the fraction that will be left after 1000 years is 
You need to divide 179.10 by 6
1,388.26-200.86=1,187.40
If she makes 79.16 you need to multiply until you get more or exactly to 1,187.40
I’m order to succeed this amount she must work (15 WEEKS) to save enough money.