liquidity needs定义为the excess of CF outflow and CF inflow，
但是在2011年Q2中，
liquidity needs在答案中写的是3.65million的debt payment而不是（8million-3.65million的差值）？
文中也并未提到继承来的8million inheritance不易变现的问题，希望老师能帮忙讲解下这块。
附上真题：
Five years have passed. Robert Becker recently died and left his estate to his only child,
Michael. Michael and his wife are both 50 years old and have no children. Michael expects to
receive his after-tax inheritance of 8.0 million U.S. dollars (USD) at the end of this year. The
Beckers both plan to retire at that time, and are meeting with Emily Frost to help them establish
an investment plan.
The Beckers currently do not have an investment portfolio and they own a home valued at
USD 3.7 million. At the end of this year, the Beckers’ outstanding debt will be USD 3.5 million
(home mortgage) and USD 150,000 (consumer debts). The Beckers will pay off their mortgage
and their consumer debts soon after the inheritance is received.