Improvement

Question 1

If someone says 12 min per km, what is the rate

Answer 1

1/12 km/min

Question 2

If you have ‘men’ that work at x rate and ‘boys’ taht work at y rate; and you have 8 men and 6 boys, you could also convert all “men” to “boy” units so that stops mattering

Answer 2

:)

Question 3

The price of the most expensive book is less than $17. if a min max problem, what would be the test case you’d use?

Answer 3

$16.99. Prices don’t have to be integers!!!

Question 4

If I tell you the following, how do you express it mathematically? The number of stamps that Kaye and Alberto had were in the ration of 5:3 respectively. After Kaye gave Alberto 10 of her stamps, the ration of the number of Kaye had to the number of Alberto had was 7:5. As a result of the gift, Kaye had how many more stamps than Alberto

Answer 4

(5x-10)/(3y+10)=7/5

Question 5

What’s 8/99? 10/99? 15/99?

Answer 5

0. 080808
1. 101010
2. 151515

Question 6

0. 0555

0. 000432432

Answer 6

5/90

432/999000

Question 7

What are the rules of a terminating decimal?

Answer 7

Denominator of a REDUCED fraction can be re-written as 2^n * 5^m. For example, 250 can be: 2*125 (checks the box)

Question 8

|s|< 5, how do you solve for this?

Answer 8

-5 < s < 5

Question 9

When is |x-4| = 4-x

Answer 9

when x<0, then |x| = -x. For example, |-3|=3, you flip sign. So in this case, because sign is flip, must be that x-4<=0, or x<=4

Question 10

what is sqrt (x^2) in modulus?

Answer 10

|x|

Question 11

What is |x| if x<0?

Answer 11

-x

Question 12

Sum of arithmetic series formula

Answer 12

Sum = n (a1 + an)/2

Question 13

Sum of geometric series

Answer 13

Sum = a1 (1-r^n)/(1-r)

Question 14

Remember that when you have a partial prime box, basically the answer is “is it divisible by 12” is

Answer 14

sometimes yes / sometimes no

Question 15

If you’re in the number line and R is left to 0, and S right to 0, but the prblem tells you, using the absolute values, what is the average

Answer 15

Then r and s becomes positive so you need to add the (-) side to r: (-r+s)/2

Question 16

DS: Is the product of all elements in set S negative? there are exactly 5 negative numbeers in the set

Answer 16

NS: what if there is a 0. (i know, bitches)

Question 17

The sum of two primes will be even (unless…?)

Answer 17

Unless one of the primes is 2

Question 18

even + even
odd + odd
even + odd

Answer 18

even
even
odd

Question 19

even x even
odd x odd
even x odd

Answer 19

even
odd
even

Question 20

Understand what the question is asking. If they say: does positive integer b have a factor n such that 1

Answer 20

No, it’s asking whether it’s not a prime basically

Question 21

Vertex of a parabola

Answer 21

(1) if in form, a(x-h)^2+k, then it’s (h,k)

2) if in form, ax^2+bx+c, then (-b/2a, f(-b/2a)

Question 22

If two lines in the coordinate have different sign reciprocal slopes, then they both form what angle?

Answer 22

ha de ser 90*

Question 23

CAT 2 mistake: The trip from Townsend to Smallville took 50% longer than the trip from Smallville to Townsend. –> if going took 2 hours, how much did coming back take

Answer 23

3. Note before you said 4!!! it was a reading problem

Question 24

In order for n/18 to be an integer, what must be true?

Answer 24

N must include all the prime factosr of 18; i.e. 3,3, and 2

Question 25

If you see something like (x) (x+2) (x+4) what testing topic comes to mind?

Answer 25

consecutive even or odd integers

Question 26

If in data sufficiency you see something like (2) 3x is divisible by 2; what might the question be testing

Answer 26

odds and evens

Question 27

the distance between two points x and y on a number line is mathematically equivalent to

Answer 27

|x-y|

Question 28

Is a multiple of N plus Multiple of N is divisible by N?

Is a multiple of N plus a multiple of non-N divisible by N?

Answer 28

yes; no

Question 29

How do you use prime factors to determine if N is divisible by A

Answer 29

N must have all the prime factors of A