I have the following practical question I guess it falls under basic arithmatic and it is not a homework. (Yes, I am kind of ashamed I don't know how to solve it myself after all these years....). Here it goes:
It is required to figure the total amount a person has kept in her account for 1 full year. Let's denot this by $R$.
She had $3$ accounts in $3$ different banks. The amount in each is shown in the picture below.
I approached this in 2 approaches hoping that the answer would be the same....:
Approach 1: for each bank, find the amount that remained 1 year in the account by calculating the minimum amoun in $2019,2020$. Repeat the process for each bank. At the end sum all these numbers to get the desired value $R3=1450$ as shown in the picuture below.
Approach 2: Sum the amounts in $2019$ in each bank, do the same for year $2020$, then calculate the minimum of the two sums. That is what is shown as $R2=1850$ in the picture below.
I thought that $R2$ will be equal to $R3$, but the values are different!!!
I understand that maybe there is no theory that says Sum (min. valuess)=Min(sum values), hwoever both approaches "make sense to me" :)
My question is which approach is in error and why?