A Neat Trick For Quickly Computing The Day Of The Week For Your Birthday

Aditya was born in 1997. From 1997 to 2013 there are 4 leap years. So we come back 16 + 4 = 20 days. She was born on Sunday.

$16 \times 365 = 5840$

There have been 4 leap years since her birth-year, so the total number of days her heart has beated is 5844.

$5844 \times 1/7 = 834$ weeks with a remainder of 6 days.

Counting back, 6 days before the Saturday was the day our Aditya came crying into this world. This will be a Sunday.

Our answer is Sunday, then. This equates to 7.

I bid you all farewell, until next time.

As he is 16 years old, he was born in $2013-16= \boxed{1997}$

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Not exactly the intent of the question, but you can use the Doomsday algorithm to find the day of the week he was born (March 2, 1997). The anchor day for the 20th century is Wednesday, and the doomsday of the year 1997 may be found by Conway's equation, where $y=97$ : $Doomsday = (\lfloor \frac{y}{12}\rfloor + y mod 12 + \lfloor \frac{y mod 12}{4}\rfloor)mod 7 + anchor$ Here, $Doomsday = (\lfloor \frac{97}{12}\rfloor + 97 mod 12 + \lfloor \frac{97 mod 12}{4}\rfloor)mod 7 + 3 = (8 + 1 + 0)mod7 + 3 = 5$ , or Friday. As the last day of February is always a doomsday, 3/2 is two days later and so its day is $\boxed{Sunday}$ .

A non-leap year has 365 days which is 52 weeks and 1 day, i.e., $365 \% 7 = 1$ . So, every year we go in the future same date occurs 1 day-of-week later unless a leap day occurs during that period.

Now, in every 4 years exactly 1 leap day appears, so the same date after 4 years appears after 5 day-of-week later.

In 16 years day-of-week changes by $4 x 5 = 20$ . Now, ( 20 \% 7 = 6). So, Aditya was born in 6 day-of-week earlier than Saturday, which is Sunday.

There are 52 weeks and 1 day in a year, except 2000/04/08/12. Those have 52 weeks and 2 days. So every 4 year passed, the day of the week will be shifted for 1+1+1+2 = 5 years.

Count from 2013 back to 1997 is 16 years (4 sets of repeated day shifted), there will be 4x5 = 20 days shifted from Aditya's latest birthday. So let's get shifted for 2 weeks and "6 days", the answer will be Sunday.

My born day is 4 * 366 + 12 * 365 days before my birthday. = 4 2 + 5 1 days (mod 7) days before my birthday. = 1 + 5 = 6 days (mod 7) days before my birthday. 6 days before Saturday is Sunday == 7.

The same day of the week comes every $7$ day
$365 \equiv 1 \pmod 7$
$366 \equiv 2 \pmod 7$
Now $2013 - 16 = 1997$ , so the leap years are $:- 2012,2008,2004,2000$
And the other years are total of $16-4 = 12$
now the day of his/her birth is like $Saturday - 12 \times 1 - 4 \times 2 \equiv Saturday - 20 \equiv Saturday - 6 \equiv Saturday + 1 \equiv Sunday \pmod 7$
Value of Sunday is 1. Then answer is $\boxed{1}$

Clearly , D.O.B is 2 March, 1997. Now, total number of days from DOB till now is x=(16*365+4) #4 leap years.

Total Incomplete repetitions in pair of 7, starting from Saturday and counting Backward, will be x%7.

Now, (16 365+4)%7 = (16%7 365%7+4%7)%7 = (2*1+4)%7 = 6%7 = 6.

So count 6 days back from Saturday which was Sunday (because 7th day was Saturday itself).

As Aditya is having his 16th birthday on 2013, he was born on 2013 - 16 = 1997. We can add the days after that day he was born on 1997 and the days that have already passed on 2013 (counting Aditya's birthday) for a total of 365, since 1997 nor 2013 are leap years. There are 4 leap years between 1997 and 2013 and 11 normal years for a total of $4 × 366 + 11 × 365 + 365 = 5844$ days. As $5844 \equiv -1 \pmod{7}$ , Aditya was born the day after Saturday, Sunday. Hence the answer is $\boxed 7$

well, if you can calculate days mentally , this problem with be easy , you don't have to go complexities

aditya birthday party arranged on march 02 ,2013.He is turning 16 years old. then, he was born in 1997(2013-16=1997). 1997 after four times leap year go(2000,2004,2008,2012) and 12 simple year(not leap year). leap year in 366 days and simple(not leap year) years in 365. each week in 7 days. simple year in week:365/7=52+1(1 day remainder) in leap year:365/7=52+2(2 day remainder). then total remainder day: 12days of simple years+(2*4)days of leap years=20 days extra.20 days weak =20/7=2+6(6 day remainder) 02 march 2013 on days is 6 day ago to aditya born day. in week 6th day means saturday at here. sunday is birthday of aditya....

Day of the week is the Saturday in a year that is the Friday in one year before (if this year is not a leap years) and is the Thursday in one year before (if this year is a leap years). Saturday, March 2, 2013 is the 16th birthday of Aditya. So, in 16 years, we have 4 leap years and 12 not leap years <=> The day we have to countdown is 4 x 2 + 12 = 20. We set Monday is 1, Tuesday is 2, v.v... Sunday is 7 <=> The loop of day of the week is 1, 2, 3, 4, 5, 6, 7. We countdown begin at 6. The result is 7

Bem , é uma questão meio complicada , não estou com paciência pra escrever em Inglês , então vai o Português mesmo , para calcular podemos usar uma jogada com a aritmética modular , Primeiramente buscamos um ano para tomarmos como medida, O melhor é buscarmos um ano que comece com o dia 1 na segunda , então eu utilizei como exemplo o ano de 1900 ,então calculamos a diferença entre a data de nascimento e a desse ano especifico , esse resultado devemos guardar ,buscando deixa-lo com algum algarismo de referencia , no meu caso eu deixei como A, então a partir dai tiramos o numero de anos bissextos , basta dividir o valor A por 4 , agora utilizamos uma tabela com base no numero de dias de cada mês , A tabela é assim: Janeiro 0 Abril:6 Julho:6( meu numero favorito é 9 eu tenho uma fixação por algarismos com 9 e com 6) Fevereiro:3 Maio:1 Agosto:2 Outubro:0 Março:3 Junho:4 Setembro:5 Novembro:3 Dezembro:5 Assim já anotado os valores anteriores, nomeando-os como bem preferirem anotem mais esse da tabela, no momento teremos 3 números , A , B e C, Agora a parte mais simples , pegamos o dia que ele nasceu e diminuímos 1, ou x-1, com isso tiramos o ultimo valor necessário , agora somamos todos e dividimos pelo numero de dias da semana , 7, e o resto da divisão equivale ao dia, sendo 0 segunda , visto que começamos o calculo pelo ano de 1900 e o primeiro dia era segunda , e então assim indo até chegar em 6 que é o domingo , porém como a resposta atura segunda como 1 então deixamos o resultado disso mais 1 igual a resposta. Resolvendo o exercício: 2013-16=97 =A 97 / 4= 24=B ( resto não é utilizado) Março=3=C 2-1=1 =D A+B+C+D= 97+24+3+1=125 125/7=6 Sexta , no caso como segunda é igual a um coloque 7 que equivalerá a sexta nessa resposta!