• Seeta, Rajinder and Surinder are children of Mr. and Mrs. Aggarwal.
• Renu, Raja and Sunil are children of Mr and Mrs. Malhotra.
• Sunil and Seeta are a married couple and Ashok and Sanjay are their children.
• Geeta and Rakesh are children of Mr. and Mrs. Gupta.
• Geeta is married to Surinder and has three children named Rita, Sonu and Raju.
What is Sanjay's surname?