Element X is a radioactive isotope such that every 18 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 500 grams, how long would it be until the mass of the sample reached 210 grams, to the nearest tenth of a year?

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %

4n=2m

ratio of m to n: 2/4 = 1/2

answer

a. 1/2

$205,000 here you go i had to guess it but i got it correct so yeah