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_25839957_5 (core_clock___mhz__ VARCHAR, memory_bandwidth___gb_s__ VARCHAR)
### Question:
What core clocks ( mhz ) have a 21.3 memory bandwidth ( gb/s )?
### Answer:
SELECT core_clock___mhz__ FROM table_25839957_5 WHERE memory_bandwidth___gb_s__ = "21.3"