Quant Flashcards
(x + y)2 =
x2 + y2 + 2xy
(x - y)2 =
x2 + y2 - 2xy
(x + y)(x - y) =
x2 - y2
(x - y)
/
(y - x) = ?
and x =/ y
-1
List the prime numbers under 100:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97
LCM (x,y) * GCF (x,y) =
LCM = Least Common Multiple
GCF = Greatest Common Factor
LCM (x,y) * GCF (x,y) = xy
LCM (x,y) = xy / GCF (x,y)
GCF (x,y) = xy / LCM (x,y)
How to tell if a number is divisible by 4:
If the last 2 digits are divisible by 4
How to tell if a number is divisible by 6:
If the number’s digits add up to 3, AND it’s an even number
How to tell if a number is divisible by 8:
If the last 3 digits are divisible by 8 (has to be even)
How to tell if a number is divisible by 9:
If the sum of the number’s digits is divisible by 9
How to tell if a number is divisible by 11:
If the sum of the odd-numbered place digits minus the sum of the even-numbered place digits is divisible by 11
How to tell if a number is divisible by 12:
If it’s divisible by both 3 and 4
Formula for division
x/y =
x/y = Quotient + remainder/y
Prime numbers from 10 to 19:
11, 13, 17, 19
0! =
0! = 1
3! =
6
4! =
24
5! =
120
6! =
720
7! =
5,040
8! =
40,320
9! =
362,880
10! =
3,628,800
In decimals, 1/6 =
0.166666