<p>The beauty of the question,however,shouldn't be disputed.I hope SAT asks such questions frequently rather than resorting to empty tricks.no?</p>
<p>it is VERY beautiful. for more beautiful questions, check out the AMCs.</p>
<p>lmao. 99% of the ppl who get 800s wouldn't be able to do so well if empty tricks were made useless on the SATs :)</p>
<p>this is a level 5 SAT question. i used trees as a last resort. yes, it was beautiful, but boy is it a pain in the a$$</p>
<p>no! it's not a pain in the ass..that's the whole point. </p>
<p>pain in the ass = brute forced ugly answer >:|</p>
<p>^^thats why they invented the graphing calculator;). and its only a pain if you don't know how to do it i guess...</p>
<p>
[quote]
I completely agree with amb3r's method.When faced with counting problems it is best to sit back and think an easier way rather making a "tree".Also one should note the distinct difference between combinations and permutations.In the above problem amber used combination not permutation.I hope this helps.
[/quote]
</p>
<p>Exactly. If you're solving the OP's question by listing out each of the 10 answers, you're not really doing the question the right way. Yes, 10 is not that many, but obviously a lot of people still made mistakes. And what if the question were changed just a little bit? "Find the number of integers between 1000-9999 with all four digits increasing, like 5689 or 3467?" You can't list out every solution, because it would take forever. The answer is so simple if you approach the question the right way. It's 9C4 = 126, just like the answer to the original question was 5C3 = 10.</p>
<p>^i doubt they would ask any harder on an SAT.</p>
<p>listing out 10 possibilities systematically isn't that hard, and you can avoid the careless mistakes if you organize</p>
<p>4567, 8, 9</p>
<p>4578, 9
4678, 9</p>
<p>4589
4689
4789</p>
<p>^you will never know.I have seen an SAT probabilty question with 72 possibilities.Check out the blue book.practice test #2?</p>
<p>LOL Narcissa...........you are an OBSESSED POSTER right?....I see you in every forum.</p>
<p>lmao yepppppp</p>
<p>ahh! here's another beautiful probability question :D
MathLinks</a> Math Forums :: View topic - Parity-Monotonic Numbers</p>