Table: railway_locomotives
Columns: locomotive
type
builder
builder_s_no
built
entered_service
withdrawn

Question: How many years entered service when there were 13 locomotives?
SQL: SELECT COUNT("entered_service") FROM railway_locomotives WHERE "locomotive" = '13'

Question: Which locomotive had a 2-8-2t type, entered service year prior to 1915, and which was built after 1911?
SQL: SELECT "locomotive" FROM railway_locomotives WHERE "type" = '2-8-2t' AND "entered_service" < 1915 AND "built" > 1911