Map units of an inverted chromosome from a non-inverted chromosome

Chromosome is A-B-C-D-E-F-G-H-I-J-K and there is an inversion with the breakpoints at the beginning of the F band and the J-I interval.

Therefore you will get: A-B-C-D-E-I-H-G-F-J-K

The question then asks:
a. If in the non-inverted chromosome the distance from E to the start of the F band was 10 map units, F-G was 30 map units, G-H was 20 map units, H-I was 20 map units and I-J was 20 map units what recombination frequency would you expect to see in an inversion heterozygote between E and H?

b. What recombination frequency would you expect to see in an inversion homozygote between E and H?

Im a bit stuck in what I am suppose to do. I thought to just assume that they were cut in the same place and replaced where the other one was, thus making a=30 map units, but I am not sure this is correct and I dont know what to do for b?

Any help would be awesome