This article explains how to use the AND function
AND(QA > 50, QB > 50)
AND(QA = 1, QB <> 1, QC > 2)
AND(logical_expression1, [logical_expression2, ...])
logical_expression2, ... - [ OPTIONAL ] - Additional expressions or references to cells containing expressions representing some logical values, i.e.
FALSE, or expressions that can be coerced to logical values.