It never Ends...Math

Test Preparation SAT Preparation
1

<ol>
<li>A train 200 meters long was traveling at a constant rate of 20 meters per second through a tunnel. It took 1 minute and 10 seconds from the time that the front of the train entered the tunnel until the time that the back of the train left the tunnel. WHat is the length of the tunnel in meters?
a.1000
b.1200
c.1400
d.1600
e.2000</li>
</ol>

<p>I used d=vt and got 1400… but the answer is 1200.WHY!</p>

<ol>
<li>If july 1 falls on a monday, then august 3 of the same year falls on what day of the week? (july has 31 days).
a.tuesday
b.wednesday
c.thursday
d.friday
e.saturday</li>
</ol>

<p>Answer is E. WHY!!?!??! also, im terrible with these sorts of questions? tips on doing them?</p>

2

<p>***, what book did u get the 2nd question from? thats unreasonable, different months have different days</p>

3

<p>19.</p>

<p>Convert 1 minute and 10 seconds into 70 seconds.
It took the train 70 seconds @ 20 m/s to travel the distance of the tunnel + 200.
Let Xi = 0.
Let Xf = distance of the tunnel + 200.
The +200 is added to Xf (final distance) because when the train stops it at a distance as long as the tunnel + the distance of the train.</p>

<p>Xf-Xi=vt
x + 200 = 20 * 70
x + 200 = 1400
x = 1200</p>

<p>The real “trick” in the question is realizing the train travels the distance of the tunnel PLUS the length of the train.</p>

4

<p>it says that the back of the train gets out of the tunnel, that means u must -200</p>

5

<p>For the first problem; You have to subtract the 200m train from the 1400m length of the tunnel and train because the train entered front first, and exited end last. So in order to calculate the length of JUST the tunnel, you must subtract the length of the train from the TOTAL tunnel AND train length (which is 1400m).</p>

<p>Sorry if my explanation is quite ambiguous. Hopefully someone will explain it in a more clear manner.</p>

6

<p>

</p>

<p>July 1 = Monday
July 8 = Monday
July 15 = Monday
July 22 = Monday
July 29 = Monday</p>

<p>July 30 = Tuesday
July 31 = Wednesday
August 1 = Thursday
August 2 = Friday
August 3 = Saturday</p>

7

<p>Add days (in 7’s to keep it on a Monday) until you reach the end of the month:
July 1
July 8
July 15
July 22
July 29 -Monday
30-Tues
31-Wed
August 1 - Thurs
2 Frid
3 Saturday</p>

<p>That’s generally how I approach these. Trying to do these quickly always made me much too error prone. This only takes about 40 seconds or so anyway.</p>

8

<p>@ravindu, the way I set up the equation it subtracts 200. I simply stated that the train traveled an extra 200m (length of the train), which also means to subtract 200 from the final distance.</p>