We will caluclate the cost per gallon first. Then, we will multiply the new quantity by this cost, so we get the new cost.
As we are told that 6 gallons costs 26.58, we can divide 26.58 by 6 to calculate the cost per gallon. It would be
Now we multiply this quantity by 18, so we get the cost of 18 gallons. It would be
so the cost of 18 gallons is 79.74
Answer is option C
Mr. Jones jogs the same route each day. The amount of time he jogs is inversely proportional to his jogging rate.
k is the constant of proportionality
We check with each option and identify which option gives us same K value
(a) 4 mph for 2.5 hours and 6 mph for 3.75 hours
so k = 10
so k = 22.5
K values are not same
(b) 3 mph for 2 hours and 4.5 mph for 3 hours
so k = 6
so k = 13.5
K values are not same
(c) 4 mph for 2.5 hours and 5 mph for 2 hours
so k = 10
so k =10
K values are same .
Answer is option C