How to do it in one request?

Question

MySQL

there are 3 requests, how do i turn them into one?
a) select countries.name, count(camps.id) from countries join camps on countries.id = camps.region_id
b) select regions.name, count(camps.id) from regions join camps on regions.id = camps.region_id
c) select cities.name, count(camps.id) from cities join camps on cities.id = camps.region_id

Answer 1

select countries.name, regions.name, cities.name, count(camps.id) from camps 
inner join countries on countries.id = camps.region_id
inner join regions on regions.id = camps.region_id
inner join cities on cities.id = camps.region_id
group by countries.name, regions.name, cities.name

Answer 2

select 
  union all
select
  union all
select

Answer 3

group by + rollup?