Question

Purchased goods from yadwinder worth 28000 at a trade discount of 25% plus VAT 10%

Answer 1

28000-25%=21000

Purchase a/c.......dr 21000
Vat A/c. .......dr. 2100
To bank or Yadwinder. 23100



NOTE:- 25% trade discount directly given by traders. So trade discount have no entry.

Answer 2

purchases = 28000- (28000*25%)
                   =21000

Journal entry 

Purchases A/c Dr       21000
Output VAT  A/c Dr       2100
     To cash/bank A/c                    23100
(being purchases goods from yadwinder)

In case of credit purchases 

Purchases A/c Dr       21000
Output VAT  A/c Dr       2100
     To yadwinder A/c                    23100
(being purchases goods from yadwinder)

hope the answer is useful