To determine which statement is NOT true about the single entry system, let's analyze each option:

• Personal, real and nominal accounts are prepared under this system.

  This statement is false. The single entry system primarily records only personal accounts, and does not fully account for real and nominal accounts. Therefore, this is the correct answer to the question.

• Trading and Profit & Loss A/C cannot be prepared under this system.

  This statement is true. In the single entry system, insufficient data is recorded, making it impossible to prepare detailed financial statements such as Trading and Profit & Loss accounts.

• Books maintained under this system are not accepted as evidence in the court of law.

  This statement is true. The single entry system is not comprehensive and fails to provide reliable and complete financial accountability, which is why such records may not be accepted in legal proceedings.

• As compared to the double entry system, this system is arithmetically less accurate.

  This statement is true. The single entry system is less accurate than the double entry system because it does not provide a complete and systematic record of business transactions.

Considering these explanations, the statement that is NOT true is: Personal, real and nominal accounts are prepared under this system.