I use these two tricks to remember it.

1) Assets make the bank money (loans. interest collected), liabilities lose money (deposits. interest paid).

2) Deposits are loans the bank takes. (As in it has to pay interest to service the "debt".)

In your example a bank with $100 in deposits is paying interest on $100, but only receiving interest on $50. In the reverse it is receiving interest on $100, but only paying interest on $50. So the reverse is much more profitable for the bank.