ABACUS International Math Competition
for
3rd and 4th graders
January, 1998
A.33. If the possible grades you can get
on a test are 1, 2, 3, 4, and 5, could a class of 30 students have an average
grade of 4.15 on this test?
A.34. Out of the numbers 1, 2, 3, 4, 5,
6, 7, 8, 9, 10 we left one number out and calculated the average of the
rest. We got 
. Which number did
we leave out?
A.35. Steve can get the following grades
in school: 1, 2, 3, 4, 5. He has only 2's, 3's, 4's, and 5's. He has at
least one but no more than two of every one of these grades. His average
is 3.4. He has a total of 5 grades. Which grade does he have two of?
A.36. The average age of the 11 players
of a soccer team is 22. One player got a red card and had to leave the game.
The average age of the remaining players of the team is 21. How old is the
player with the red card?
A.37. Out of the following group of numbers
take the fewest possible numbers with a sum of 100.
5, 17, 19, 37, 39, 46, 66
A.38. Is left or right the forward direction
for this bus (with seven windows on one side, as seen on the picture), if
you drive on the right hand side of the street?
A.39. We used 2775 digits to number the
pages of a book. How many pages are there in this book?
A.40. You can see the following pictures
if you look at a solid object from the top and from the right hand side.
There are no drawings or holes on the object. What would the front view
of this object look like?
Please, send your solutions to:
Solutions of previous
problems