adding specifics columns and rows

[Guest]

How do I add if I have in column B2 23, B3 34, B5 20, B7 16, and in column
C4 14, C6 30 if I put in column A2 a, A3 a, A4 c, A5 b, A6 c, A7 b. Total
sum in column B for all rows that are a only, total in column B for all rows
that are b only total sum in column C for all rows that are c only. Can it be
done in excel?
Thank u again

 

[Guest]

check your answer in your previous post.