Two cars leave a gas station at the same time, one traveling north and the other south. the northbound car travels at 50 mph. after 3 hours the cars are 345 miles apart. how fast is the southbound car traveling? a. 60 mph b. 65 mph c. 70 mph d. 75 mph

For this case we have:

We define the following variable

x : Speed of the car in South direction

By definition, we know that:

For the car in north direction:

For the car in south direction:

The distance between both cars, after 3 hours, is:

So, we have:

Clearing x;

Thus, the speed of the car in the south direction is

Option B

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

40 minutes

step-by-step explanation:

add the time and multiply by 2