Answer :
$425 is the amount of simple interest that you would have gained after one year found by using the simple interest formula of s(1±i)^t s=starting amount i=interest amount t=time in years so if we input are numbers 8500(1+.05)^1 which equals 8925 now subtract 8500 to get the amount that you gained. And 22.5 grams Enjoy!=)
the answer is 22.5 because you multiply 450 and 50 together to get 22500 and for every milligram that equals .001 grams so after multiplying that you multiply 22500 by 1000 and you get 22.5
