ABACUS International Math Challenge
for
3rd and 4th graders
December, 2006
A.561. In the Amusement Park the fairy
train's 3 cars are being put together. They have 2 red, a blue and 2 yellow
cars to choose from. How many different trains can they put together if
they want to have at least one red car in the train?
A.562. There is a group of kids waiting
for the go carts. They are calculating that if one kid sits in every go
cart then 4 kids will have to wait outside, but if 2 kids sit in every go
cart then 1 go cart stays empty. How many go carts and how many kids are
there if there are 2 seats on every go cart?
A.563. One kid brought a $100 bill to the
park for the rides, but he has to break it to $50, $20 or $10 bills. How
many different ways can they break it for him if it is possible that he
does not receive all 3 kinds of bills?
A.564. On the giant ferries wheel Pete
and his friends are sitting in the 3rd basket , facing the 12th basket.
The baskets are evenly spread out on the wheel. How many baskets are there
on the wheel?
A.565. The children have a great time in
the Castle of Mysteries. In the mirror room and the maze room there are
26 children all together. In the mirror room and the ghost room there are
22 children all together. There are 20 children in the maze room and in
the ghost room all together. These are the only 3 rooms in the castle. How
many children are there in the castle?
A.566. Oliver tried 4 rides in the park,
one after the other. At each ride he spent half of his money plus 40 cents.
How much money did he take to the park if he went home with $1.00 and he
did not spend money on anything but rides?
A.567. Out of all the fourth graders, 26
went in the Castle of Mysteries, 29 went on the roller coaster, and 24 went
on the giant ferries wheel. 20 kids were both in the Castle of Mysteries
and on the roller coaster, 18 were on both the roller coaster and the giant
ferries wheel, and 16 were both on giant ferries wheel and in the Castle
of Mysteries. 11 children went to all three places, and everybody went to
at least one place. How many fourth graders went to the park?
A.568. In the Amusement Park Danny and
his friends are throwing rag balls at a tower of cans. A can falls down
if you hit it or if any of the two cans right below it falls down. At least
how many cans do you have to hit and which ones in order for the sum of
the numbers on the cans fallen to be 50?
Please, send your solutions to: