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.
Learn more about and in one of the following articles