Blue Robin Retail has one store in Ottawa and one in Regina. All sales in Ontario are subject to 13% HST; all sales in Saskatchewan are subject to 5% GST and 6% PST. On March 12, 2024, the Ottawa store reports cash sales of $7,200 and the Regina store reports cash sales of $8,400. 

(a) Calculate the sales taxes each store charged for these sales. 

(b) Prepare a journal entry for each store to record the sales on March 12, 2024.