Several people are standing in a straight line . Starting at one end of the line , bill is counted as 5th person , and starting at the other end , he is counted as the 12th person. How many people are in the line?

Draw this to make sure you don’t get messed up. Let’s use X for all the people in line who aren’t Bill and B for Bill. X X X X B X X X X X X X X X X X Above, Bill is the 5th person from the left and the 12th person (more…)

The volume of right circular cylinder A is 100cm. What is the volume in cm of a right cylinder with half of the radius and twice the height of cylinder..?

The volume of a cylinder (this formula is given to you in the beginning of every math section) is: So if the volume of a particular cylinder is 100 cm^3, you know this: Now apply what the question says to what you know. Cut the radius in half and double the height: But wait—we can (more…)

how many different positive 4-digit numbers can be formed with the digits 2,3,4 and 5 if each digit is to be used exactly once in each number?

Note that questions like this don’t appear on the SAT, but they might appear on a SAT Subject Test. For the first digit, you have four choices: 2, 3, 4, or 5. Once you choose that first digit, you have three choices for the second digit. Once you’ve chosen the first and second digits, you (more…)

on friday , janice read x pages every 30 minutes for 4 hours , and kim read y pages every 15 minutes for 5 hours . which of the following represents the total number of pages read by janice and kim on friday?

If Janice reads x pages every 30 minutes, then she reads 2x pages per hour because there are 2 30-minute periods every hour. Because Janice reads for 4 hours, she reads 4(2x) = 8x pages. Likewise, if Kim reads y pages every 15 minutes, then she reads 4y pages per hour. Because Kim reads for 5 hours, (more…)

six distinct points lie in a plane and no three of them are collinear how many different line segment may be drawn connecting pairs of these points ?

This is a counting question, which used to appear on the old SAT (pre-2016) but don’t appear on the current SAT. I just wanted to point that out before getting into it because I didn’t want to scare anyone. I assume you’re prepping for a Subject Test (or maybe even GRE or something like that). (more…)