From the question statement, we know that the bank has ten branches. We are trying to find the total amount of assets under management at the bank. Since we know the number of branches of the bank, if we are able to calculate the total assets managed by each branch, we will be able to answer the question.
From statement I alone, there is an average of 400 customers per branch.“When each branch’s average assets under management per customer is computed, these values are added together and this sum is divided by 10. The result is $400,000 per customer.” – Lot of data, let us try to break it down.
Let the total asset under management in branch #1 be \(T_1\). Since each branch has 400 customers,
Average assets under management per customer in branch#1 = \(\frac{T_1 }{ 400}\).
Similarly, for the other branches, it will be \(\frac{T_2 }{ 400}\), \(\frac{T_3}{400}\) and so on. When we add this and divide it by 10, we get,
\(\frac{T_1+T_2+T_3+… + T_{10} }{ 4000}\). The statement says that this is equal to $400,000. Equating, we get,
\(T_1+T_2+T_3+…… + T_{10}\) = $1600,000,000 i.e. $1600 million. Therefore, statement I alone is sufficient to find the total amount of assets under management at the bank.
Answer options B, C and E can be eliminated. Possible answer options can be A or D.
From statement II alone, the bank has a total of 4000 customers (this works out to 400 customers per branch on an average, which is the same data given in statement I). Also, each branch is found to manage $160 million of assets on average. Therefore, the total assets under management is equal to $160 million multiplied by 10 i.e. $1600 million, which is the same value we got from statement I alone as well.
Statement II alone is sufficient. Answer option A can be eliminated.
The correct answer option is D.
Hope that helps!