Answer:
Y(OH)₃
Step-by-step explanation:
Given ions: 
 Y³⁺ OH⁻
To find a neutral compound that conforms with the formation of the given ions; 
We us the exchange of valency approach to solve this problem. The valency will form the combining power of the ions for the combination. 
 Y³⁺ OH⁻
Combining power 3 1 
Exchange of valency 1 3 
 Now the compound is Y(OH)₃