Answer:
Cassie has 40 marbles, 16 red marbles and 24 yellow marbles
Step-by-step explanation:
If Cassie has 8 red marbles and 12 yellow marbles and they are doubled. We can calculate the total amount of marbles cassie has.
[tex]=2\cdot{8}+2\cdot{12}=16+24=40{/tex]
Cassie has 40 marbles, 16 red marbles and 24 yellow marbles