<p>1) Average snow base of x inches, at the end of each day, 1/5 of the snow base left from the previous day melted. Four days later what was the remaining snow base in inches?
I picked (1/5)x but the answer is (256/625)x</p>
<p>2) How do I do this?
n does not equal 0 and 125n^x is equal to n^(x+3), then 125n = ?</p>
<p>I’d appreciate any explanations!</p>
<p>1) Since 1/5 melts each day, after each day you have 4/5 remaining. Four days go by, and for each day for have 4/5 of the previous day’s amount. So, do (4/5)^4 times x, which gives you (256/625)x.</p>
<p>2) There might be an easier way, but this is what I have:
125n^x = n^(x+3)
125 = (n^(x+3)) / (n^x)
125 = n^(x+3-x)
125 = n^3
n = 5</p>
<p>125(5) = 625</p>
<p>Thank you! Is there an alternate way to do #1?</p>
<p>It’s not as fast as shalooky’s solution but…</p>
<p>You could make up a number for x…say 100. Then, multiply by 4/5 (or.8) to see what’s left at the end of the day. You’ll get 80, then 64, then 51.2 and finally 40.96.</p>
<p>Then stick x=100 into each answer choice…rule out anything that isn’t 40.96 and you will have your answer.</p>
<p>
</p>
<p>That is obviously correct, but visually it might be easier to write down </p>
<p>4x4x4x4 / 5x5x5x5 (x is for multiply and not for x 
)
and that is
256 / 625</p>
<p>I am not sure it is important to look for a different way, as the solutions above are more or lesss what this type of problem requires. Not sure where the problem came from, but it does not read like a true SAT problem. But I am an old timer!</p>