A spreadsheet lists projects in column A and number of days in column B, rows 2 to 7: A-15, A-20, B-30, A-10, B-10, A-5. What is the output of the formula =SUMIF(A2:A7, "A", B2:B7) in cell C1?

SUMIF adds column-B values only for rows where column A equals A, namely the days 15, 20, 10 and 5.

Those four matching entries total fifty, since fifteen plus twenty plus ten plus five is fifty.

The value 90 would come from adding every row, wrongly including the B projects.

The value 80 corresponds to no correct selective total of the A rows.

The value 20 counts far too few of the matching entries.

SUMIF tests each cell of the criteria range and sums only the aligned cells of the sum range.