<p>In focus mode, what type of question is the kind of question where it goes "how many of ______ are in 1-1000?" or something like that. Also any tips on those types of questions would be greatly appreciated.</p>
<p>Could I have an example?</p>
<p>like this?</p>
<p>From the 2009 PSAT:
</p>
<p>i see no better alternative than to plug and chug</p>
<p>consider 3 digit numbers first, the first digit can be anything except 0 or 7, so 1,2,3,4,5,6,8 and 9, so 8, second digit can be any number except 7, as can the third, so there are 9 possibilities for both those=648 3 digit numbers
Then 2 digit numbers, first digit has 8 possibilities, 2nd has 9, so 72 possibilities
Then 1 digit numbers, which would be 1,2,3,4,5,6,8 and 9
Total=8+72+648=728 so C</p>
<p>@AstroBlue cool. thanks!</p>
<p>If you want a quicker method, the first digit can be anything but 7, so 9 digits, same for the 2nd and third so the number of choices is 9x9x9=729, which is wrong, but only 1 off of 728 so just go chose C</p>
<p>^
The reason it’s one off is because 000 is not an acceptable number</p>