Math&job

Successive increase or decrease

formula is

Ultimate Result = A+B+(AB/100)

negative result means ultimate decrease, positive result means ultimate increase.

Example

a Shirt price first increased 8% then decreased 10%, what is ultimate discount or profit for seller?

A= 8 ; B= - 10 (negative sign for decrease)

Ultimate Result = A+B+(AB/100)

=8 + (- 10) + {8(-10)} /100

=8 - 10 + (-80)/100

= - 2 - 0.8

= - 2.8

So it is finally ends up with 2.8% discount

formula is

Ultimate Result = A+B+(AB/100)

negative result means ultimate decrease, positive result means ultimate increase.

Example

a Shirt price first increased 8% then decreased 10%, what is ultimate discount or profit for seller?

A= 8 ; B= - 10 (negative sign for decrease)

Ultimate Result = A+B+(AB/100)

=8 + (- 10) + {8(-10)} /100

=8 - 10 + (-80)/100

= - 2 - 0.8

= - 2.8

So it is finally ends up with 2.8% discount

Math&job

Hands of a clock

Math&job

Clock Math

Master piece formula for clock related math.

Angle between hour hand and minute hand = (60*H-11*M)/2 when hour more than 6

Angle between hour hand and minute hand = (11*M-60*H)/2 when hour less than 6

here, H=hour, M=minute

Example: At 10.25 am angle between hour and minute hand is ?

Ans: angle=(10*60-11*25)/2 = 162.5 degree

Reflex angle= (360-162.5)=197.5 degree

Angle between hour hand and minute hand = (60*H-11*M)/2 when hour more than 6

Angle between hour hand and minute hand = (11*M-60*H)/2 when hour less than 6

here, H=hour, M=minute

Example: At 10.25 am angle between hour and minute hand is ?

Ans: angle=(10*60-11*25)/2 = 162.5 degree

Reflex angle= (360-162.5)=197.5 degree

Math&job

Divisibility

Divisible

by 2: if the last digit is even or zero , then the number is divisible by 2

example : 578 here last digit is 8 which is even so 578 is divisible by 2

by 3 : if sum of all digit of a number is divisible by 3 then the number is also divisible by 3

example: 261, here 2+6+1=9 which is divisible by 3 so 261 is also divisible by 3

by 4: if the last two digit is divisible by 4 , then the number is divisible by 4

example : 35516, here last two digit is 16 which is divisible by 4 so 35516 is also divisible by 4

by 5 : if the last digit is 5 or zero , then the number is divisible by 5

example : 11570 here last digit is 0 so the number is also divisible by 5

by 6 : if the number is divisible by both 2 and 3 then the number is also divisible by 6

example: 738 is divisible by both 2 and 3 so the number is also divisible by 6

by 2: if the last digit is even or zero , then the number is divisible by 2

example : 578 here last digit is 8 which is even so 578 is divisible by 2

by 3 : if sum of all digit of a number is divisible by 3 then the number is also divisible by 3

example: 261, here 2+6+1=9 which is divisible by 3 so 261 is also divisible by 3

by 4: if the last two digit is divisible by 4 , then the number is divisible by 4

example : 35516, here last two digit is 16 which is divisible by 4 so 35516 is also divisible by 4

by 5 : if the last digit is 5 or zero , then the number is divisible by 5

example : 11570 here last digit is 0 so the number is also divisible by 5

by 6 : if the number is divisible by both 2 and 3 then the number is also divisible by 6

example: 738 is divisible by both 2 and 3 so the number is also divisible by 6

Math&job

Divisibility

Divisibility

By 8 : if the last three digit is divisible by 8 , then the number is divisible by 8

example : 35516, here last two digit is 516 which is divisible by 8 so 35516 is also divisible by 8

by 9 : if sum of all digit of the number is divisible by 9 then the number is also divisible by 9

example: 261, here 2+6+1=9 which is divisible by 9 so 261 is also divisible by 9

by 11 : if the difference between the sum of its digit in odd place and the sum of its even place is either 0 or a number divisible by 11.

example: 8470, here the sum of the odd placed digit =0+4=4

the sum of the even placed digit =7+8=15

So the difference is= 15-4=11

So, 8470 is also divisible by 11.

By 8 : if the last three digit is divisible by 8 , then the number is divisible by 8

example : 35516, here last two digit is 516 which is divisible by 8 so 35516 is also divisible by 8

by 9 : if sum of all digit of the number is divisible by 9 then the number is also divisible by 9

example: 261, here 2+6+1=9 which is divisible by 9 so 261 is also divisible by 9

by 11 : if the difference between the sum of its digit in odd place and the sum of its even place is either 0 or a number divisible by 11.

example: 8470, here the sum of the odd placed digit =0+4=4

the sum of the even placed digit =7+8=15

So the difference is= 15-4=11

So, 8470 is also divisible by 11.

You have your own theory, idea, experience, style but Hesitated to express if people laugh at. It could be world winning theory or style, who knows! so reveal it for other. Let the people know it.