Answer:
wrong as his calculation was incorrect at initial level itself when he found the result of the division
Step-by-step explanation:
Andre said
3 ÷ 



but andre calculated it as



Hence his calculation was incorrect at initial level itself
To calculate the remaining caffeine, we use the radioactive decay formula which is expressed as An = Aoe^-kt where An is the amount left after t time, Ao is the initial amount and k is a constant we can calculate from the half-life information. We do as follows:
at half-life,
ln 1/2 = -k(6)
k = 0.12/hr
An = 80e^-0.12(14)
An = 15.87 mg
The easiest way to tell if a number is rational or not is to attempt to express it as a fraction. If you can, then the number is rational. If not, then the number is irrational. All integers are rational numbers, because they can be written as a fraction (for example, the integer 8 = 8/1). But numbers like pi or sqrt(2) cannot be written as a fraction and are not rational.
This is difficult
Step-by-step explanation: