Step-by-step explanation:
Houses are numbered from 1 to 99. So, there are 99 houses. Odd-numbered houses are on the left. So, there are 50 houses on the left, while there are 49 houses on the right.
For houses on left : The houses are numbered 1, 3, 5, 7, 9, 11, 13..... 97, 99
So 5 houses( 1, 3, 5, 7, 9) require only one plate for numbering, while the remaining 45 houses require 2 plates each. So total number of plates = =
plates.
For houses on right : The houses are numbered 2, 4, 6, 8, 10, 12, 14.... 96, 98
So 4 houses( 2, 4, 6, 8) require only one plate for numbering, while the remaining 45 houses require 2 plates each. So total number of plates = =
plates.
∴ There are 45 houses on the left and require 95 plates, while there are 44 houses on the right and require 94 plates.