A commercial bank with assets of $2 billion and expenses of $200 million has acquired an investment

Question:

A commercial bank with assets of $2 billion and expenses of $200 million has acquired an investment banking firm subsidiary with assets of $40 million and expenses of $15 million. After the acquisition, the expenses of the bank are $180 million and the expenses of the subsidiary are $20 million. Does the resulting merger reflect economies of scale or economies of scope?