He included another variable - time. He should have given both brands the same amount of time to work. The only variable should have been the brands. Parker has introduced another variable and therefore his results are invalid.
Answer: 5 hours
Step-by-step explanation: first subtract 354.7 - 200.35 = 154.35
then divide 154.35 by 30.87 which is equal to 5
hope this helps mark me brainliest if it helped
Answer:
The Answer is C hope this helps!
Step-by-step explanation: