Answer:
 $887.50
Step-by-step explanation:
Her gross pay is the sum of the pay amounts for each of the hour amounts:
 pay = 40(12.50) +18(12.50)(1.5) +2(12.50)(2)
 = (12.50)(40 +18(1.5) +2(2)) = 12.50(40 +27 +4) = 12.50(71)
 pay = 887.50
Barbara's gross pay for the week was $887.50.