Answer:
1 hour
Step-by-step explanation:
The time it takes to travel to a destination varies inversely as its speed
T= k/S
K= TS
Time= 2 hours
Speed= 40mph
K= 2×40
= 80
Therefore if the average speed changes to 80mph then the new travel time can be calculated as follows
T= 80/80
= 1 hour
Hence the new travel time is 1 hour
means to say there is some
such that
. Similarly,
is equivalent to saying there exists
![k_2[/te]x such that [tex]n=dk_2](https://tex.z-dn.net/?f=k_2%5B%2Fte%5Dx%20such%20that%20%5Btex%5Dn%3Ddk_2)
.
Now,
, i.e. there is some
such that
is a multiple of
, i.e.
.
