Answer:
Quantity remaining= 27.5 grams
Step-by-step explanation:
If the initial quantity of the radioactive isotope= 220 grams
And for each half life it will reduce to half of its original quantity
For first half life
Quantity= 220/2
Quantity= 110 grams
Now for the second half life , the quantity to work with will be 110 grams
Second half life
Quantity= 110/2
Quantity= 55 grams
For the third half life , the quantity to work with is 55 grams
Third half life
Quantity= 55/2
Quantity= 27.5 grams
So after 3 half life's of this radioactive isotope, the amount remaining out of 220 = 27.5 grams.
Another simple way to do this
Since half life reduce the isotope by half of its original.
The third half life will reduce it by (1/2)^3= 1/8
So the quantity remaining= 1/8*220
Quantity remaining= 27.5 grams
Answer:$90
Step-by-step explanation: $30 is the cost. 200 is the percent of Mark-up, so you take 100 percent of 30 and add it together then you get 60. Repeat that step for a total of 90. 100 percent of 30 is 30. So 30+ 30+ 30 = 90.
Answer: 
Step-by-step explanation:
To find the inverse, you replace the x with y, and y with x.
[add 5 on both sides]
[divide both sides by 11]
<span>3pi is an irrational number; the other options are not.</span>
