Petty Cash Fund - please explain #2 and #3 in detail because I don't understand.

2 . A $ 300 petty cash fund has cash of $39 and receipts of $255 . The journal entry to replenish the account would include a . debit to Cash for $255 b . credit to Petty Cash for $255 C . debit to Petty Cash for $261 d . credit to Cash for $261 account would be 3 . A $150 petty cash fund has cash of $21 and receipts of $126 . The journal entry to replenish the a . Cash 126 Petty Cash 126 b . Miscellaneous Expenses 126 Cash Over and Short Cash 129 C . Miscellaneous Expense 126 Cash Over and short Petty Cash 129 d . Miscellaneous Expenses 129 Cash Over and Short Cash 126