Answer:
$12.6 per hour
Step-by-step explanation:
There are total of 15 workers, ( 7 + 3 + 5).
The total earning per hour is as below
Cashiers : 7 x $12 = $84
Stockers : 3 x $10 = $30
Salespeople : 5 x $15 = $75
Total earning per hour
= $84 +$30 +$75
=$189
Average earning = $189/15
=$12.6 per hour