Answer :
Answer:
55mph . None of the options are correct
Step-by-step explanation:
If the speed varies inversely as the time it takes to drive, then v ∝ 1/t. where;
v is the speed
t is the time taken
Hence;
v = k/t with k being the constant of proportionality.
Since it takes Kris 5 hours when driving at 55 mph, we will substitute v = 55mph and t = 5 hours. into the equation above to get the value of k as shown:
55 = k/5
Cross multiply
k = 55*5
k = 275
Hence, to calculate the speed it will Martin to drive for 5 hours, we will substitute k = 275 and t = 5 into the original equation v = k/t as shownl
v = 275/5
v = 55 mph
Hence, we can conclude that Martin will also need to drive at a speed of 55mph if he wants to take 5hours.