To find how long it would take him, one has to divide 400 by 160 and then multiply 5 by what that number is. You multiply 5 by the quotient because that is the number that would make it proportional. 400/160 x 5 is 12.5, meaning that the answer is 12.5 minutes, or A.
Answer:
1/18
Step-by-step explanation:
1/6 * 1/3
1 *1 = 1
6 * 3 = 18
1/18
Answer: 
Step-by-step explanation:
Use the power rule for differentiation.
Answer: 
<u>Step-by-step explanation:</u>
