ABACUS International Math Challenge

for

5th and 6th graders

December, 2000

 

B.217. Find more than two consecutive integers that have a sum of 11.

 

B.218. Find a positive whole number that can be written as the product of six consecutive whole numbers, and also as the product of three consecutive whole numbers.

 

B.219. Is there such a whole number that starts with the digit 7, and it triples when you move its first digit to the end of the number?

 

B.220. If I divide the year of the birth of one of my ancestors by 11, 12, and 13, and I add the remainders, I get 33. In what year was my ancestor born?

 

B.221. How many different triangles have whole number-long sides if none of the sides is longer than 4 units?

 

B.222. You have a 2, 4, 6, and a 7 units long segment. Using any of these four segments as many times you want, how many different triangles can you make?

 

B.223. Roll a regular die, with the numbers 1, 2, 3, 4, 5, and 6 on it, four times in a row, and add the four numbers. Then repeat this many times. What number do you expect to appear as the sum the most often?

 

B.224. Amanda received a calculator for her birthday. Immediately, she started to add up the whole numbers starting with 1. Soon she saw the number 3000 appearing on the screen, and she showed it proudly to her older sister, Sarah. But Sarah ruined her happiness by saying that Amanda forgot to add a number. What number is Sarah talking about?

 

Please, send your solutions to:

tdiveki@gcschool.org

 

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