MySQL
SELECT SUM(QTDAGE) AS TOTALAGE, SUM(QTDINS) AS TOTALINS, SUM(QTDLOC) AS TOTALLOC FROM
(
select COUNT(*) AS QTDAGE, 0 AS QTDINS, 0 AS QTDLOC FROM JPANPAGE
UNION ALL
select 0 AS QTDAGE, count(*) AS QTDINS, 0 AS QTDLOC from JPANPINS
UNION ALL
select 0 AS QTDAGE, 0 AS QTDINS, count(*) AS QTDLOC FROM JPANPLOC
) AS SOMA