Answer:
$390
Step-by-step explanation:
First Roberto works 32 hours at 6.50 per hour. At that time, he earn 32*6.5 = $208. Then he works 8 hours at a time and a half. This means that his pay rate is 50% more, or 6.5*1.5 = $9.75 per hour. Since he worked 8 hours at this pay rate, he earns 8*9.75 = $78. And then he works 8 hours double time. This means his pay rate was doubled during that duration. 6.5*2 = 13, 13*8 = $104.
Total: 208 + 78 + 104 = $390
