Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_29218221_2 (rider VARCHAR, tues_31_may VARCHAR)
### Question:
What is the number of riders that had a Tues 31 May time of 18' 55.91 124.236mph?
### Answer:
SELECT COUNT(rider) FROM table_29218221_2 WHERE tues_31_may = "18' 55.91 124.236mph"