Let us break the adjustment into three components:
1. Write-off of bad debts:
Debtors proved bad = ₹60,000
This must be directly debited to Revaluation A/c.
$\Rightarrow$ Revaluation A/c Dr. ₹60,000
2. Adjustment of provision for bad debts:
Debtors after writing off = ₹8,00,000 – ₹60,000 = ₹7,40,000
Required provision @10% = ₹74,000
Existing provision = ₹50,000
$\Rightarrow$ Additional provision = ₹74,000 – ₹50,000 = ₹24,000
This increase in provision is also debited to Revaluation A/c.
3. Total debit to Revaluation Account:
= Bad debts written off + Additional provision
= ₹60,000 + ₹24,000 = ₹84,000
Hence, the total amount debited to the Revaluation A/c = ₹84,000.