Dear Md Aejaz,
I apologize for not been clear and I hope this quickly compiled example can be of help (Product A-E are to be purchased from vendors x1-x4). Here I have also included a price, but the initial problem is to minimize the number of vendors.

Product Vendor Price

A x1 10
x3 15

B x2 11
x3 12

C x1 15
x2 10
x4 12

D x3 13
x4 13

E x1 12
x4 10

regards,
Jowi