For the arithmetic sequence
a₁, a₂, a₃, ..., 
The n-th term is

where d = common difference.
Because a₁₀ = 41,
a₁ + 9d = 41                (1)
Because a₁₅ = 61
a₁ + 14d = 61             (2)
Subtract (1) from (2).
5d = 20
  d = 4
From (1), obtain
a₁ = 41 - 9*4 = 5
Therefore
a₃ = 5 + 2*4 = 13
Answer:  a₃ = 13
 
        
        
        
        
-15228 I think but let me know if I’m wrong please
        
             
        
        
        
I think 128????? my best guess