ABACUS International Math Challenge
for
3rd and 4th graders
September, 2002
A.321. The 8-eyed diverspiders love to
feed on one-eyed winkylobsters. A few of the diverspiders are sneaking up
on a group of winkylobsters right now. The 15 animals have a total of 36
eyes. How many diverspiders are hunting, and how many winkylobsters are
in the group?
A.322. Three mudbugs, Sleepy, Slimy and
Slippery, are participating in a 50 cm long distance running race. How many
different outcome is possible if even a tie is allowed?
A.323. Four little children are collecting
colorful pebbles. Tony collected 35 more than Timmy, but 52 less than Teri.
Timmy collected 63 pebbles, exactly 5 less than the half of what Tibi collected.
How many pebbles did they collect all together?
A.324. A spider is making a web. He picks
three out of the following 9 flowers, and surrounds them with a line. This
way he can make several triangles with different sizes. How many?
A.325. A water spider is building his underwater
castle out of air bubbles. He can take 12 air bubbles under water in 3 minutes.
In 2 hours he is done. How many bubbles are there in the castle if every
10th bubble escaped?
A.326. There is a long line, a telephone
cable, connecting the castles of two water spiders. Snail estimated it to
be 142 cm long, Mussel thought is was 120 cm long, Dragonfly thought it
was 128 cm long, and Ladybug thought it was 136 cm long. One of them was
mistaking by 2 cm, another by 12 cm, yet another by 10 cm, and the fourth
by 6 cm. How long is the line?
A.327. A travelling mussel wanted to visit
one of his relatives. The first day he made half of the way and one more
meter, the second day he made half of the remaining distance and 2 more
meters, the third day he made half of the yet remaining distance and 3 more
meters. So, for the fourth day he just had 8 more meters to go. How far
did his relative live?
A.328. A man, driving from New York to
Florida, wants to sleep in a motel where 12 rooms have a total of 32 beds.
Some rooms have 2 beds, the others have 3 beds in them. How many rooms have
2 beds and how many have 3 beds in this motel?
Please, send your solutions to: