Two trains leave the station at the same time, one heading east and the other west. the eastbound train travels 20 miles per hour slower than the westbound train. if the two trains are 800 miles apart after 4 hours, what is the rate of the eastbound train?

90 mph

Step-by-step explanation:

Let the speed of the westbound train (A) be x mph; and

the speed of the eastbound (B) train be (x-20) mph.

We know that distance = speed x time

so distance traveled by A = 4x; and

the distance traveled by B = 4 (x - 20) = 4x - 80.

Adding these distances up to get:

4x + (4x - 80) = 800

4x + 4x = 800 - 80

8x = 720

x = 720/8

x = 90

Therefore, the rate at which the eastbound train travels is 90 mph.

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)