Answer:
It will take 13.58 minutes until there are 80 grams of the element remaining
Step-by-step explanation:
An element with a mass of 990 grams decays by 16.9% per minute.
We are supposed to find how long will it be until there are 80 grams of the element remaining
Formula :
N(t)=Amount after t minutes
=Initial amount
r = rate of decrease = 0.169
t = time in minutes
Substitute the values in the formula :


t=13.58
Hence It will take 13.58 minutes until there are 80 grams of the element remaining
We are comparing areas, so square of the linear dimension
Relative cost per unit area
12^2/6=24
16^2/10=256/10=25.6
Since 24<25.6, the 12" pizza is a better deal.
Note: we could compare exact area by calculating A=pi (d^2)/4, but since it is a relative comparison, the result will be the same, albeit more work.
1 One and two hundred sixty-eight thousandths
2 two thousand 4 hundred fifty-six and ninety-eight hundredths
3 thirty-four thousand five hundred sixty-eight and two tenths
The answer is c
Explanation Ik it