Answer:
Unit rate of area of blackboard to area of poster =
Unit rate of area of Poster to area of blackboard = =
Explanation:
Rates help us to evaluate or compare two different quantities.
Unit rate help us to compare or know that how the units of the quantity 1 is related to units of quantity 2.
We are given that:
Area of Blackboard =

Area of Poster =
Unit rate of area of blackboard to area of poster: It mean that how does unit area of blackboard is related to or corresponds to area of poster

=

Thus, 1 unit area of blackboard corresponds to

Unit rate of area of Poster to area of blackboard: It mean that how does unit area of poster is related to or corresponds to area of blackboard.

=

Thus, 1 unit area of Poster corresponds to
