Home » Difficult Riddles » When the celebrated German mathematician Karl Friedrich Gauss (1777-1855) was nine he was asked to ad...

When the celebrated German mathematician Karl Friedrich Gauss (1777-1855) was nine he was asked to add all the integers from 1 through 100. He quickly added 1 to 100, 2 to 99, and so on for 50 pairs of numbers each adding to 101. Answer: 50 X 101=5,050. What is the sum of all the digits in integers from 1 through 1,000,000,000? (That’s all the digits in all the numbers, not all the numbers themselves.)

0 0

Share with


Facebook Comment

You may also like..

Two sentries were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, “Why are you smiling?” How did he know that his companion was smiling?

0 0

What do you call a sleepwalking nun?

1 0

Lazy Larry agreed to work on a job for his brother-in-law for thirty hours at eight dollars an hour, on the condition that he would forfeit ten dollars per hour for every hour that he idled. At the end of the thirty hours Larry wasn’t owed any money and didn’t owe his brother-in-law any money either. How many hours did Larry work and how many hours did he idle?

0 0

How is Europe like a frying pan?

0 0
Previous      Next  

Submit a Comment

Your email address will not be published. Required fields are marked *