I need a function to get final value in min.sec.

[Astrotech]

Substract 82.30 - 72.50 (Type Degree)
Answer require : 09.40 (Type Degree)
Multiply : 09 x 4 Second
Ans : 36 Min
Multiply : 40 x 4 Second
Ans : 160 Second
convert : 36 Min.160 Sec
as 36 Min. + 2 Min 40 Second
Final Ans require : 38 Min. 40 Sec

[Luuk]

Can you explain in words what you are trying to do?
I am alrady loast at your second sentence:
"Answer require : 09.40 (Type Degree)"

You need a 'final value in min.sec', but do not specify what 82.30 and 72.50 is.

What correlation has 'Degree' with min.sec. ?

[SioSio]

Conversion from Integer type to TimeSpan Type

Dim imin As Integer = 82
Dim isec As Integer = 30
Dim ts1 As New TimeSpan(0, imin, isec)

Time calculation (adjustment)

Dim ts1 As New TimeSpan(0, 82, 30)
Dim ts2 As New TimeSpan(0, 72, 50)
Dim ts3 As TimeSpan = ts1 - ts2

Convert

Dim ts3 As New TimeSpan(0, 36, 160)

Time calculation(multiplication)

Dim L As Long  = ts1.Ticks * 7

To Striing

Dim min As String = Mid(ts3.ToString,4,2)
Dim sec As String = Mid(ts3.ToString,7,2)

[cactusdata]

You can handle your degrees as timespans:

Dim StartValue As TimeSpan = New TimeSpan(0, 72, 50)
Dim StopValue As TimeSpan = New TimeSpan(0, 82, 30)
 
Dim Factor As Double = 4
Dim Final As TimeSpan = TimeSpan.FromSeconds(StopValue.Subtract(StartValue).TotalSeconds * Factor)
 
Console.WriteLine(Final.ToString("mm':'ss"))
 
' -> 38:40