Formula Flashcards
Divisor
Can be divided by that number
Divisors would be 1 and that number itself
Eg. 4 -> 1, 2 ,4
15 -> 1, 3 ,5, 15
Combination
Out of 10 possibility of 2
10C2 = 10!/2!8! = 10*9/2
Total Percent Increase
Total Increase/Original Total Production
Percentage Increase
Multiplier for r percent increase r+1
Probability of a thing happening twice
Example probability of getting six twice in dice
1/6 *2
In Percentage, x % greater and x % lesser how is it calculated
Greater will add to the original value, for eg 80% greater means than 100 means, 100+(0.8100) = 180
30% lesser than 180 means
180(30-100/100) = 180*0.7 = 126
Calculate the number of numbers between m to n inclusive
n-m+1
If a fraction is undefined
The denominator will be zero
Percentage Increase by P%
1+P% as decimal
Eg 20% increase from 800
1+0.20 = 1.20
800*1.20 = 960
Percentage Decrease by P%
1-P% as decimal
Eg 20% decrease from 800
1-0.20 = 0.80
800*0.80 = 640
Percentage of pf increase/ decrease
m=new/old
m=1+P for increase
m=1-P for decrease
Where P is the increase or decrease percentage
Percentage increase p and then decrease q from there in x money
Then Final = x(1+p)(1-q)
Example 100 money 30% inc and 30% dec
Final = 1001.30.7
Simple Interest Formula
In Simple interest, the interest will be only based on the principal. No matter whatever the interest accumulates.
If for 1000 in account, 5% interest,
Interest = 50
1st year 1000+50 = 1050
2nd year 1050+50=1100
3rd year 1100+50=1150
Compound interest
Interest on interest
Always greater than SI
A = P(r)^y
Where A = Final Amount
P - Principal
r - rate of interest in multiplier format (7% - 1.07)
r = 1+I/100 = 1+7/100
y - number of years
Compound Interest for smaller period in a year
Quarterly n=4
Half Yearly n=6
Everyday n=365
Now if the interest is I%
It will become I/n for each period
Thus if total interest is 5% it will become 1.25% each
r=(1+I/100n)
Amount A = P(r)^yn
