Answer:
176m.u.
Step-by-step explanation:
Map distance can be calculated by the following formula:
Map distance =

Recombinant offsprings are redeyes, miniature wings + white eyes, long wings.
Recombinant offspring = 40 + 48
=88.
Total number of offspring = 204 + 208 + 40 + 48
= 500
Map distance =

Map distance = 176 m.u.
The map distance between two genes is 176 m.u.