Answer:
 46 cm
Step-by-step explanation:
Let p represent the length in cm of 1 bap'ai; let k represent the length in cm of 1 bok'ai. Then we have ...
 12p +2k = 100
 10p +10k = 100
Subtracting the second equation from 5 times the first, we get ...
 5(12p +2k) -(10p +10k) = 5(100) -(100)
 50p = 400
 p = 8 . . . . cm
Then the second equation tells us ...
 10(8) +10k = 100
 10k = 20
 k = 2 . . . . cm
Then 5p+3k = 5(8) +3(2) = 46 cm.
The distance 5 bap'ai and 3 bok'ai is 46 cm.