We count Skittles logo face up(are decomposing) and Skittles facing down( are put back into the cup to shake again).
total Skittles= 113 parent isotope.
#of parent atomes
1 half-life(7mins later)= 50
2half-lives(7 mins later)= 26
3 half-lives(7mins later)=12
4 " " =4
5 " " = 2
6 " " = 1
7 " " = 0
# of daughter atomes
1 half-life(7mins later)= 63
2half-lives(7 mins later = 24
3 " " = 14
4 " " = 8
5 " " = 2
6 " " = 1
7 " " = 0
0