Respuesta :
So the answer is sorta simple here:
Since Leah Put 21 white marbles, 31 black, and 7 blue if her sister added 19 add 21+31+7+19 and itll get you 78 marbles all together
Since Leah Put 21 white marbles, 31 black, and 7 blue if her sister added 19 add 21+31+7+19 and itll get you 78 marbles all together