The numerals 1,2,4,5,7,8 are marked one on each side of three counters so that the sum of the numerals on any particular counter is 9. The counters are drawn at random one-by-one from box, each counter being tossed after it is drawn then with the uppermost faces unchanged, placed side-by-side on a table (in the order which they are drawn) to form a three digit number.
i. Show that the probability the three-digit number formed is a multiple of 3 is 1/4.
ii. If the random trial described above is performed several times, find the probability that the second three-digit number multiple of 3 occurs on the 5th trial.
Thanks
i. Show that the probability the three-digit number formed is a multiple of 3 is 1/4.
ii. If the random trial described above is performed several times, find the probability that the second three-digit number multiple of 3 occurs on the 5th trial.
Thanks