A juice bottle costs \(₹\)\(3x + 8\), where \(x = 5\)
 
Shreya calculates:
 
\(3x + 8\) \(= 3 + 5 + 8 = 16\)
 
Mind the mistake: Identify Shreya's mistake. 
 
Mend the mistake: Find the correct cost(in \(₹\)).