When n/a is the cash fate and n/a is the 31-day pass how many types of fare are there?
CREATE TABLE "fares" (
  "type_of_fare" text,
  "cash_fare" text,
  "day_pass" text,
  "31_day_pass" text,
  "monthly_pass" text
);
SELECT COUNT("type_of_fare") FROM "fares" WHERE "31_day_pass"='N/A' AND "cash_fare"='N/A';