Question

Write a VB program to find out twin prime numbers between 10 to 100. Twin primes are defined to be two consecutive odd numbers, which are prime (Accept input through textbox and display result on form)

Answer 1

Write a VB program to find out twin prime numbers between 10 to 100. Twin primes are defined to be two consecutive odd numbers, which are prime

Explanation:

A Twin prime are the numbers with following properties:  

1. Numbers must be prime
2. There must be difference of two among the two prime numbers.

Example:

(3,5) , (5,7) , (11,13) and (17,19)

Program

Dim n1 As Integer

Dim n2 As Integer

Dim i As Integer

Dim flag As Boolean

Private Sub Command1_Click()

flag = False

n1 = Val(Text1.Text)

n2 = Val(Text2.Text)

If n1 > 10 And n2 < 100 Then

While n1 <= n2

For i = 2 To n1 \ 2

If n1 Mod i = 0 Then

flag = True

End If

Next

If flag = True Then

MsgBox ("Either of the number is not prime")

End

Else

cnt = cnt + 1

n3 = n1

n1 = n1 + 2

flag = False

End If

If cnt = 2 Then

If n3 = n2 Then

MsgBox "No1 and no2 are twin primes"

Else

MsgBox "No1 and no2 are not twin primes"

End If

End

End If

Wend

End If

End Sub

Private Sub Text1_Click()

Text1.Text = ""

End Sub

Private Sub Text2_Click()

Text2.Text = ""

End Sub