\begin{tabular}{lrr} & \begin{tabular}{l} WATERWAY LTD. \\ Adjusted Trial Balance (partial) \\ January 31, 2024 \end{tabular} & \\ & Debit & Credit \\ \hline Supplies & $640 & \\ Prepaid insurance & 1,140 & \\ Equipment & 6,600 & \\ Accumulated depreciation-equipment & & $2,750 \\ Income tax payable & & 160 \\ Deferred revenue & & 800 \\ Service revenue & 110 & 1,890 \\ Depreciation expense & 380 & \\ Insurance expense & 910 & \\ Supplies expense & 100 & \\ Income tax expense & & \\ \hline \end{tabular} If the amount in Supplies Expense is the amount of the January 31 adjusting entry, and $800 of supplies were purchased in January, what was the balance in Supplies on January 1? (Hint: Prepare the adjusting journal entry for this transaction, post to the Supplies and Supplies Expense T accounts, and work backward to determine the opening balance.) The balance in supplies $