Answer:
15!
Step-by-step explanation:
so 40 people volentered to bring cakes, but 10 brought 2. So (30*1)+(10*2)=50 cakes. So, 30 percent of 50 cakes would be 15. To double check, times 50 by 100 and then 30 percent would become 30 (making super sure the actual answer is 15)