PLEZ HALP WITH THESE! DST

Algebra
Tutor: None Selected Time limit: 1 Day

I NEED HELP! 

1:

For a ship moving against the current, it takes 9 hours to cover a distance of 113.4 miles. How much does it take this ship to return if the rate of the current is 1.9 mph?

2: 

Two trains move between two towns. It takes the first train 2 hr 48 min and it takes the second 4 hr 40 min. The rate of the first train is 26 mph more than that of the second train. What is the distance between these towns?
Apr 10th, 2015

1.  Let  x = speed of the ship without current

Then, moving against the current

x - 1.9 = 113.4/9

x - 1.9 = 12.6

x = 14.5 mph

moving with the current the ship's speed is 14.5 + 1.9 = 16.4mph

therefore the time it takes to return is

113.4/16.4 = 6.9 hours


2.  Let x = rate of the first train

Let y = rate of the second train

then, x = y + 26

distance = (rate)(time)

For the first train

distance = 2.8x

For the second train

distance= 4.67y

but both distances are the same, so

2.8x = 4.67y

Now substitute x for y+26

2.8(y+26) = 4.67y

2.8y + 72.8 = 4.67y

1.87y = 72.8

y = 38.93 mph

so, the distance = (38.93)(4.67) = 181.8 miles

Apr 10th, 2015

Hey, umm, sorry, but the second one wasnt right. Could you do it again? Thanks, and sorry for all the hassle 

Apr 10th, 2015

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Apr 10th, 2015
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Apr 10th, 2015
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