Given the rationale, provide a reasonable question and answer. Step-by-step reasoning process: Half of Tanya's 20 erasers are red, so she has 20 / 2 = 10 red erasers. One - half as many erasers as Tanya has red erasers is 10 / 2 = 5 red erasers. Rachel's three less than one - half as many erasers as Tanya's red erasers, which is 5 - 3 = 2 erasers. Hanna has twice as many erasers as Rachel, for a total of 2 * 2 = 4 erasers.
The question and answer:
Hanna has twice as many erasers as Rachel. Rachel has three less than one-half as many erasers as Tanya has red erasers. If Tanya has 20 erasers, and half of them are red, how many erasers does Hanna have?
The answer is 4