ABACUS International Math Challenge
for
3rd and 4th graders
March, 2000
A.177. Cow Moo has red, white, and black
spots on her new dress. All but two spots are red, all but two spots are
white, and all but two spots are black. How many spots are there on her
dress?
A.178. The ages of grandma's two grandchildren
are the same as the digits of grandma's age. The three of them are 72 years
old all together. How old is grandma?
A.179. What is the last digit of the product
of the difference and the sum of the smallest 2000-digit number and the
largest 1999-digit number?
A.180. Students in a class were making
globes. A girl began to wonder in how many different orders she could glue
the continents on a globe. Can you tell her?
Susann Melinda Almasi, 4th grade
A.181. Find the greatest 6-digit number
in which the digits, starting from the third digit, are the products of
the previous two digits.
A.182. In some numbers the product of the
digits is the same as the product of the first and last digits. How many
such 3-digit numbers are there?
A.183. You have a few consecutive positive
whole numbers. If you leave one of the numbers out, and add the rest of
them, you can get 2000. How many numbers could you originally have the most?
by Bognár Ferencné, Hungary
A.184. Barbie mommy and Barbie daddy were
playing chess. They agreed that after every game the winner gets 5 points,
the looser gets zero points and everybody gets 2 points for a tie game.
They played 13 games and received a total of 60 points. Barbie mommy received
three times as many points for the games that she won than for the tie games.
How many games did Barbie daddy win?
Please, send your solutions to: