Answer:
The number is 9.
Hope you could get an idea from here.
Doubt clarification - use comment section.
[tex]\huge{\purple{\underline{\underline{\bf{\pink{ANSWER:-}}}}}}[/tex]
Let the no. be x.
[tex]:\implies\tt{3x + 5 = 32} \\ \\ \\ :\implies\tt{3x = 32 - 5} \\ \\ \\ :\implies\tt{3x = 27} \\ \\ \\ :\implies\tt{x = \frac{27}{3} } \\ \\ \\ :\implies\tt{x = 9}[/tex]