how to you answer this i have no clue please help....

E3.12 Journalise basic transactions and adjusting entries. LO4 Selected accounts of Snowmass Ltd are shown here: Supplies expense Supplies July 31 500 July 1 Bal. 1 100 July 31 500 10 200 Salaries payable Service revenue receivable July 31 1 200 July 31 500 Salaries expense Service revenue received in advance July 15 1 200 July 31 900 July 1 Bal. 1500 31 1 200 20 700 Service revenue July 14 3 000 31 900 31 500 Required After analysing the accounts, journalise (a) the July transactions and (b) the adjusting entries that were made on 31 July. (Hint: July transactions were for cash.)