ABACUS International Math Challenge
for
3rd and 4th graders
March, 2005
A.481. There are 26 students in Melinda's
class. In the Spring Break 8 of them went to Florida to see Mickey Mouse,
18 of them went to a sailing camp, but 5 children did not go anywhere. How
many students went to both Florida and to a sailing camp?
A.482. Four kids are building sand castles.
Everybody's castle is a different height. They made the following true statements
about the castles:
Fanny: My castle is not higher than Suzanne's.
Eva: Suzanne's castle is not smaller than Katie's.
Katie: Eva build a smaller castle than Fanny.
Suzanne: Eva's castle is not the smallest.
Put the castles in an increasing order of their heights.
A.483. Each of 5 children won a bag of
18 chips at a play land. The chips worth $2 or $5 each. We have the following
information about the bags:
- Mike's bag contains the same number of $2 and $5 chips.
- Gabe has two more $2 chips than $5 chips in his bag.
- Tom has two more $5 chips than $2 chips in his bag.
- Joe has twice as many $2 chips than $5 chips in his bag.
- Bea has twice as many $5 chips than $2 chips in her bag.
Whose bag is worth the most?
A.484. There are 24 toys you can rent at
a stand on the beach: 8 pedal boats, 10 kayaks, and 6 surf boards. 6 of
them are already rented out. Figure out which of the following statements
about the toys that are not rented out yet are true for sure, maybe true,
or not true:
a) There are not more surf boards.
b) Any of the three kinds of toys is still available.
c) There is still at least one more surf board available for rent.
d) There is still at least one more pedal boat available.
e) There are not more pedal boats.
f) There are at least two more kayaks available.
A.485. 23 kids went for a boat ride. Every
kid had his or her mom on the trip, too. How many mothers were on the trip
if we know that 5 kids have no siblings, 8 kids have one sibling with them
on this trip, 6 kids have two siblings with them on this trip, and 4 kids
have three siblings with them on this trip?
A.486. Fanny wants to eat berry and lemon
ice cream, therefore, she pushes the yellow and red buttons on the ice cream
machine. Sue wants chocolate, raspberry and lemon, therefore, she pushes
the yellow, blue and green buttons on the machine. Emma pushes the white,
and the green buttons because she wants pistachio and raspberry ice creams.
Which buttons should Anetta push if she wants to eat chocolate and raspberry
ice cream?
A.487. An older and a younger Indian sit
on a cliff overlooking a beautiful lake. All of a sudden, the older Indian
gets up, then the younger one does the same, and they walk down to the lake.
There they get in a boat and paddle into the middle of the lake, where the
younger Indian say to the older one: "I am your son, but yet you are
not my father." How could this be?
A.488. Teresa and her family stayed at
a 5-story hotel on their vacation. On every floor there are the same number
of rooms, except for the ground floor where there are 12 rooms.. The rooms
on the ground floor are numbered by 1 through 12. The rooms on the upper
floors (first through 5th floor) are marked by 3-digit numbers where the
first digit indicates the floor number, and the last two digits indicate
the number of the room on that floor. For example: the number of the 4th
room on the 3rd floor is 304. How many rooms are there in this hotel on
each of the floors above the ground floor if they used 255 digits to number
all the rooms in the hotel?
Please, send your solutions to: