To solve this we are going to use the half life equation

Where:

is the initial sample

is the time in years

is the half life of the substance

is the remainder quantity after

years
From the problem we know that:



Lets replace those values in our equation to find

:




We can conclude that after 1600 years of radioactive decay, the mass of the 100-gram sample will be
91.7 grams.
R is greater then or equal to18
The formula of an area of a square:

a - a side
We have 
substitute:

Used:

Answer:
230
Step-by-step explanation:
54+4×22×2
54+88×2
54+176
230
Answer:
6
Step-by-step explanation: