Quant Flashcards
1/6
0.167
1/7
0.143
1/9
0.111
How do you determine the number of solutions (quadratic)
Look at the value of b^2-4ac:
Positive: 2
0:1
Negative:0
In quadratic equation, what is the sum of 2 solutions
-b/a
In quadratic equation, what is the product of the two solutions
c/a
Divisibility rule of 2
If the units digit is even
Divisibility rule of 3
The sum of all the digits is divisible by 3
Divisibility rule of 4
If the last 2 digits of a number are divisible by 4
Divisibility rule of 5
The last digit is 0 or 5
Divisibility rule of 6
If the number in question is an even number whose digits sum to a multiple of 3
Divisibility rule of 8
If the number is even, divide the three last digits by 8
Divisibility rule of 9
The sum of all the digits is divisible by 9
Divisibility rule of 11
If the sum of odd-numbered place digits minus the sum of the even placed-digits is divisible by 11
Divisibility rule of 12
If a number is divisible by 3 and 4
How do you determine the number of trailing zeros
The number of 5x2 pairs
Find the value of n when 21!/3^n
Divide 21/3 = x
Divide 21/3^2 = y
Until we cannot divide 3^n by something, you then do the sum of x,y …
How do you use the shortcut to determine the number of n in x! when it is even
You just need to break the non-prime number into prime factors and just use
When determining the units digits for numbers, what is the maximum number of combinations
4
Approximate square roots:
2,3,5,6,7,8
14.
1.7
2.2
2.4
2.6
2.8
Approximate cube roots
2,3,4,5,6,7,9
1.3
1.4
1.6
1.7
1.8
1.9
2.1
Approximate fourth roots
2,3,4,5,6,7,8,9
1.2
1.3
1.4
1.5
1.6
1.6
1.7
1.7
Special trick when adding like bases with equal exponents
4 * 4^n = 4^(n+1)
The product of any n consecutive integers is always divisible by
n!
The product of consecutive even integers is divisible by
2^n *n!
How do you know the value of p*q
Multiply the LCD and GCF
In a problem of constant growh, make sure to look at whether it is increasing by a constant amount or constant growth factor.
If it is a constant amount: x + #y
If it is a constant factor: xy^#
What is the difference between simple and compound interest
The simple is : principalratetime
The compound is : P(1+r/n)^(nt)
There is also one very important thing about the interest
It is always on 100.
Exponential growth problems
Initial value * growth^n
Digits problems
The value of any 2 digit number will follow the equation:
10a+b = x
What is the reverse number
10b+a = ba