To Think or Not to Think

[adilsaleem]

If you were to spell out numbers (starting from 1) in English, how far would you have to go until you would find the letter "A"?

 

[adilsaleem]

What is the remainder left after dividing 1! + 2! + 3! + … + 100! By 7?

Think carefully !!!

Its not all that difficult

 

[aca_trader]

What are next two numbers in the series

2, 12, 360, 75600, -, -

tough one ...

2 -- 2^1
12 -- 2^2*3^1
360 -- 2^3*3^2*5*1
75600 -- 2^4*3^3*5^2*7^1
174636000 -- 2^5*3^4*5^3*7^2*11^1
5.24432E+12 -- 2^6*3^5*5^4*7^3*11^2*13^1 (The no. Generated by Excel, if somebody wants, it can be translated into pure number.

2,3,5,7,11, 13 are the Prime Numbers in ascending order.

Best Regards,
--Ashish

 

[aca_trader]

What is the remainder left after dividing 1! + 2! + 3! + + 100! By 7?

Think carefully !!!

Its not all that difficult

It's equal to reminder of (9.4269E+157) divided by 7.

 

[pkjha30]

If you were to spell out numbers (starting from 1) in English, how far would you have to go until you would find the letter "A"?

Thousand

regards
Pankaj

 

[pkjha30]

great going Pankaj , here is another one for all ...

In 1990, a person is 15 years old. In 1995, that same person is 10 years old.

How is this possible?

He was born in 2005 BC
In 1995 he was 10 years old
In 1990 he was 15 years old
2005BC------->>1995 BC----->>1990 BC--------->>1 AD------------------------>>2006AD
Pankaj

 

[pkjha30]

and another one ...

What is the largest possible number you can write using only 2 digits? (any two digits once or same digit twice)

In Roman Numerals

MM = 2,000,000 * 1000=2,000,000,000

In Arabic Numeral

(9^9)!

Pankaj

 

[pkjha30]

What is the remainder left after dividing 1! + 2! + 3! + … + 100! By 7?

Think carefully !!!

Its not all that difficult

5

pankaj

 

[aca_trader]

5

pankaj

Pankaj,
Can you please tell me how this 5 was derived?? I am wondering since morning.

Regards,
--Ashish

 

[pkjha30]

Pankaj,
Can you please tell me how this 5 was derived?? I am wondering since morning.

Regards,
--Ashish

1!+2!+3!+4!+5!+6!=1+2+6+24+120+720=873/7=124 remainder=5

Rest all factorials have 7 in them so fully divisible by 7 without remainder.

regards
pankaj