select
    count(d.sId) as 'count(*)'
from
    (
        select
            SC.sId,
            avg(score)
        from
            SC
            inner join Course as c on SC.cId = c.cId
            inner join Student as s on SC.sId = s.sId
        where
            cname in ('语文', '数学', '英语')
        group by
            SC.sId
        having
            avg(score) > 60
    ) as d