PLEASE HELP WILL MARK BRAINLY

.In the zombie apocalypse, the ratio of children to adults was 3 to 4. The ratio
of adults to zombies was 4 to 5. If there were 200 zombies, then how many
children were there?

2. (4^5)(4^−7) = 4^?

3. . What is the circumference and area of the circle? Use 22/7
for π. Radius=42cm