Table: marseille_quartiers_age
Columns: quartier
0_19_years
20_39_years
40_59_years
60_74_years
75_years_and

Question: How many o-19% are where the quartier is in saint-loup?
SQL: SELECT "0_19_years" FROM marseille_quartiers_age WHERE "quartier" = 'Saint-Loup'

Question: how many 20-39% are in pont-de-vivaux?
SQL: SELECT COUNT("20_39_years") FROM marseille_quartiers_age WHERE "quartier" = 'Pont-de-Vivaux'

Question: the quartier menpenti has how many 40-59 year olds?
SQL: SELECT "40_59_years" FROM marseille_quartiers_age WHERE "quartier" = 'Menpenti'