72 minutes
convert 8 hours to minutes ⇒ =8 × 60 = 480 minutes
15% of 480 = 0.15 × 480 = 72 minutes
Answer: 80
Step-by-step explanation: If he is 20% complete, then 20 x 5 is 100. So if we want to get 100%, then we have the multiply. Now he did 16 questions, so we have to multiply 16 five times. 16 x 5
Hoped this helped!