ABACUS International Math Challenge
for
3rd and 4th graders
October, 2003
A.385. In a Kennel Club there are 85 dogs.
They are either white, gray old colorful. Actually, 7 of them are white
and 1/6 of the the rest of the dogs are gray. How many colorful dogs are
there in the Club?
A.386. Your math teacher said: "Today
is my birthday, and 20 years from now I will be twice as old as I was 10
years ago." How old is she now?
A.387. Broomy, the old polar bear, slipped
off of a cliff. On the steep wall of ice he climbs up 5 meters during the
day, but slips back down 4 meters every night. How many days does it take
him to get out of this 20 meters deep whole?
A.388. Four little baby seals, Slippy,
Duffy, Fatty, and Puffy, organized a sliding competition for themselves.
After the competition they said the following to their father:
Slippy: "Fatty won."
Duffy: "Unfortunately, I was not the best."
Fatty: "Duffy won."
Puffy: "I did not win."
Then they told him that one of them lied and the other three told him
the truth. Who lied, and who won the competition?
A.389. Four Eskimos, Sumi, Jorg, Mork,
and Beni, summarized the results of their day of fishing: Sumi did not catch
more fish than Jorg.Beni caught less than Jorg. Jorg caught the same amount
as Mork. Mork caught more than Sumi. Beni did not catch more fish than Sumi.
Who caught the most fish and what was the order after that?
A.390. Three Eskimos are paddling in a
fishing boat when all of a sudden they hit a rock and the water starts coming
into their boat. 18 liters of water came into the boat in 3 minutes. The
Eskimos know that if they have more than 30 liters of water in the boat,
they will sink. Therefore, two of them started to get the water out of the
boat with their buckets, and the third Eskimo started paddling towards the
shore. One of them takes out 3 liters of water every minute, the other takes
out 5 liters of water every two minutes. Will they reach the shore before
they sink if it takes the paddler needs 30 minutes to get them to shore?
A.391. Three Eskimos are building an igloo
from ice blocks. The strongest Eskimo brings half of the ice blocks necessary
and two more. The middle one brings half of the rest and two more. The weakest
Eskimo brings the remaining 20 blocks. How many ice blocks do they use for
the igloo?
A.392. The little Eskimos organized a kayak
race. In case of how many competitors could we have less than 30 different
outcomes if there are no ties at any place at the finish line?
Please, send your solutions to: