SQL

Consider the following database table named water_schemes:

water_schemes
scheme_no   district_name   capacity
1           Ajmer           20
1           Bikaner         10
2           Bikaner         10
3           Bikaner         20
1           Churu           10
2           Churu           20
1           Dungargarh      10

The number of tuples returned by the following SQL query is ________.

with total(name, capacity) as
    select district_name, sum(capacity)
    from water_schemes
    group by district_name
with total_avg(capacity) as
    select avg(capacity)
    from total
select name
    from total, total_avg
    where total.capacity ≥ total_avg.capacity