Answer:
 The conversion cost per equivalent unit is $3.31
Explanation:
The computation of the conversion cost per equivalent unit is shown below:
 = Total conversion costs ÷ Total equivalent units 
where, 
Total conversion cost = completed units + Conversion costs during April
                                     = $6,000 + $35,000 
                                     = $41,000
And, the total equivalents units equal to
= Finished good units × percentage of completion + ending work in process units  × percentage of completion
= 11,500 units × 100% + 1,500 units × 60%
= 11,500 units + 900 units
= 12,400 units
Now put these values to the above formula  
So, the per unit would equal to
= $41,000 ÷ 12,400 units
= $3.31 per unit