Question 42120
Let car speed = 'v' mph and distance traveled = 's' miles.
[As the amount of fuel remains constant (= 10 gallons) so it will not come in any equation.]
As distance traveled varies inversely as the speed, so
{{{s = k/v}}}________(1)
where k = constant of variation.


When v = 50, s = 300.
Put this in eqn.(1).
Thus we get
{{{300=k/50}}}
or k = 15000


So, putting the value of k eqn(1) becomes
{{{s=15000/v}}}________(2)


When v = 60 from (2) we get
{{{s=15000/60}}} = 250


The reqd. distance is 250 miles.