ARRAY(...)

Category: Math and trigonometry

Adds its arguments

SUM(number1,[number2],...)

Category: Math and trigonometry

Adds the cells in a range that meet multiple criteria

SUMIFS(sum_range, criteria_range1, criteria1, [criteria_range2, criteria2], ...)

1

This formula adds up quantities of goods ordered by either of the two customers. In our example either Carl Ludwig or Barry French