Mahajana Mathematics Competition Sample Grade 8 ________________________________________________________________

Transcription

Mahajana Mathematics Competition Sample Grade 8 ________________________________________________________________
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
Part A
(10 Questions, each question is worth 2.5 marks)
1. The second largest number in the set {0.3, 0.9, 0.18, 0.27,
0.081} is
(A) 0.8
0.3
2.
0.9
(B) 0.9
(C) 0.3
(D) 0.27
3
(A) 3
Equals
(B) 0.3
(C) 0.03
(D) 0.003
3. A student using an electronic calculator mistakenly multiplies
by 10 instead of dividing by 10. The incorrect answer on display
is 600. The correct answer is
(A) 0.6
(B) 6
(C) 60
(D) 6000
4. The Canadian dollar was equivalent in value to $0.98 in
American currency. The value of one American dollar in
Canadian currency at that time was
(A) $1.0204
(B) $1.025
(C) $1.180
5. The arc lengths of three semicircles are
as shown on the right side figure. The area
of the shaded region is
(A) 18
(B) 9
(C) 36
(D) 72
(D) $1.144
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
6. Ram was walking home from shop
when he realized he had forgotten buy
milk for his mother.
He walked back to the shop, bought milk
and then walked home. The graph shows
his distance from home at different
times.
The total distance Ram walked is
A) 1000 meters
B) 1100 meters
C) 1200 meters
D) 1400 meters
7. The circle graph shows the favorite ice
cream flavors of those surveyed in Sir John
McDonald Collegiate. In the above survey,
the fraction of students who selected either
chocolate or Vanilla as their favorite flavour
of ice-cream is
A) 2/3
B) 3/4
C) 1/2
D) 5/8
8. A room having dimension of 12m long, 8m wide and 10m
high, is to have the wall and ceiling painted. Each paint
container covers 250 square meters of surface area. The number
of containers needed to paint one coat is
(A) 2
(B) 3
(C) 4
(D) 6
9. Triangular numbers follow this
pattern: As shown, the first four
triangular numbers are 1, 3, 6, and
10. The seventh triangular number is
(A) 36
(B) 28
(C) 25
(D) 21
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
10. A perfect number is an integer that is equal to the sum of all
of its positive divisors, except itself. For example, 6 is a perfect
number because 6 = 1 + 2 + 3.
Which of the following is a perfect number?
(A) 10
(B) 13
(C) 24
(D) 28
Part B
(10 Questions, each question is worth 4.5 marks)
11. The “Rectangle 1”, “Rectangle 2”, and “Rectangle 3” are
arranged to form the following sequence of rectangles as shown
below:
The above rectangles are formed by 1cm by 1cm squares. Many
more rectangles are drawn, with each rectangle having one more
row and two more
columns than the previous rectangle.
How many 1cm by 1cm squares would there be in Rectangle 4?
A) 28
B) 45
C) 40
D) 35
12. The coordinates of the vertices of
rectangle PQRS are given in the diagram on
the right side. The perimeter of rectangle
PQRS is 44.
The value of p is
A) 12
B) 10
C) 15
D) 14
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
13. In the diagram on right side, AB=6cm,
AC=4cm, the value of CD is
(A) 7.8
(B) 7.2
(C) 6.8
(D)5.8
14. The figure shown can be folded along the lines
to form a rectangular prism. The
surface area of
the rectangular prism is 280 cm2.
The length is
(A) 3cm
(B) 5cm
(C) 8cm
(D) 10cm
15. Mark has a bag that contains 3 black marbles, 6 gold
marbles, 2 purple marbles, and 6 red marbles. Mark adds a
number of white marbles to the bag and tells Susan if she now
draws a marble at random from the bag, the probability of it
1
3
being black or gold is .
The number of white marbles that Mark adds to the bag is
(A) 5
(B) 2
(C) 6
(D) 10
16. In 2010 Mahajanans Contest
Grade 8, the marks of 32
mathematics students on Test
are all multiples of 10 and are
shown on the bar graph below.
What was the average (mean)
mark of the 32 students in the
class?
A) 70
B) 74
C) 68
D) 76
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
17. Steve completes a job in 8 days. Arun completes the same
job in 12 days. Steve and Arun together complete the same job in
(A) Less than 5 days
(B) Less than 6 days
(C) More than 6 days
(D) More than 8 days
18. The volume of a cylinder is equal to the area of the bases
times the height of the cylinder (π r2 h). The volume, in cm3, of
the largest cylinder which will fit inside a cube 10 cm by 10 cm
by 10 cm
(A) 25π
(B) 100π
(C) 250π
(D) 500π
19. In the figure on the right side formed by one unit
square blocks, the Point B is the midpoint of AC and
the Point D is the midpoint of CE.
The line which passes through the point P and one of
the point A, B, C, D, & E cuts the area of the shape
into two pieces of equal area.
(A)Point D
(B) Point B
(C) Point A
(D) Point C
20. A single piece of string is laced through a hole in
a piece of cardboard. The top side of the card is
shown. One of the diagrams below, that could not be
the underside of the card is
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
Part C
(5 Questions, each question is worth 6 marks)
21. A cube having an edge length of 10 cm is sliced
in to two sections by a cut in the plane ABC,
as shown in the diagram. Find the volume
of the smaller section
(A) 225.6
(B) 166.6
(C) 500
(D) 750
22. The shape “S “shown on the right side is
Constructed from four semicircles. B & D
are the centers of the semi circles on the
left side of AE and the radius is 2r. On the
right side of AE, the larger circle radius is 3r
and smaller circle radius is r. When the
length is increased by 8 times, the new area
of the shape “S “is increased by:
A) 8
B) 16
C) 32
D) 64
23. In Bourbon College, Saimala receives the
following marks out of 100 in seven of her eight
courses. When Samantha actually finds out her
French mark, it turns out that her average in all
eight courses is 85.
What is her actual French mark?
A) 86
B) 92
C) 100
D) 96
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
24. In the tile pattern, there are three tiles in horizontal row and
one tile below this row. Another row of three tiles is added to the
top of each consecutive figure. The correct set of figures for the
above data is
(A)
(B)
(C)
(D)
25. In the triangular pattern of numbers shown on
the right side, every row begins with a 1 and ends
with a 2. Each of the numbers, not on the end of a
row, is the sum of the two numbers located
immediately above and to the right, and immediately
above and to the left. For example, in the fourth
row the 9 is the sum of the 4 and the 5 in the third
row.
If this pattern continues, the sum of all of the numbers in the 7th
row is
A) 1228
B) 192
C) 245
D) 189
Mahajana Mathematics Competition Sample
Grade 8
________________________________________________________________
Bonus Questions (10 marks)
The addition shown below, representing 2 + 22 + 222 + 2222 + _
_ _, has 101 rows and the last term consists of
101 two's:
(a) Determine the value of the ones digit A.
(b) Determine the value of the tens digit B and
the value of the hundreds digit C.
(Write down all steps).
Good Luck!