Answer:
60.5 milligrams per square centimeter First, determine how many half lives have expired by dividing the time by the half-life. So: 55/20 = 2.75 That means that only 2^(-2.75) = 0.148650889 = 14.8650889% of the original substance remains. So just divide the amount remaining by 0.148650889 to get the original amount. 9 / 0.148650889 = 60.5445419 So originally, there was 60.5 milligrams per square centimeter 55 years ago.
Let the integers be x-2, x, x+2.
Given,
x -2 + x + x + 2 = 69
3x = 69
x = 23
Hence, the integers are 21, 23 and 25.
Answer:
3.5C = 1n
Step-by-step explanation:
For every $3.5 is 1 mile.
I do not know what other currency this could be, as I only live in the US. Therefor, i'm assuming it's US Dollars. But this does not effect the question, so moving on.
Brainliest for being like only a fortnight late...?
After 45 minutes you will have painted 4*45=180 square feet.
so the total number of painted area, y, is:
y=180+x*(3+4) after the 45 minutes
where x is the number of minutes AFTER THE 45 minutes:
if y is 1000 then
1000=180+x*7
820=x*7
x=117.14
so 117 minutes, or one hour and 57 minutes.
