SASMO 2018 Secondary 2 (Grade 8) Contest

Question 1

Evaluate 8 x 4 x 125 x 5.

1. 2000
2. 20000
3. 4000
4. 40000
5. None of the above

Question 2

The digits of a two-digit number are switched. The resulting number is 75%
more than the original number. Which of the following is a possible value of the
original number?

1. 21
2. 28
3. 24
4. 48
5. None of the above

Question 3

Given x ‹ 0, simplify the expression
x? + (-14) Voax?

1. x + 4x
2. x + 8x
3. x—4x
4. —x — 8x
5. -—x-4x

Question 4

Find the next fraction in the sequence below.
115 5 17 13
32'3'7' 016"
ae
& B. %
G g
d.2
E, None of the above

1. E. None of the above
2. See the source image for option B.
3. See the source image for option C.
4. See the source image for option D.
5. None of the above

Question 5

The least common multiple (LCM) of two positive integers is 384. If the ratio of
: the two positive integers is 3:8, find their highest common factor (HCF).

1. 12
2. 16
3. 24
4. 32
5. None of the above

Question 6

Thursdays of a certain month have the most number of dates which are prime
S numbers. Which day of the week is the 13" of this month?

1. Monday
2. Tuesday
3. Wednesday
4. Thursday
5. None of the above

Question 7

If the five-digit number A67A0 is divisible by 60, find A.

1. 2
2. 4 CG. 6
3. See the source image for option C.
4. 8
5. None of the above

Question 8

Tania is about to win a prize in a game. She is holding a standard 6-sided dice
which would determine the prize she will get.

e She will get a \$100 cash if she rolls 5 or 6.

e If she rolls an even number, then she will need to flip a coin. If the coin
shows a head, she will get a book prize. If it shows a tail, she will get a
chocolate package.

e If she rolls an odd number, she will get a gift voucher.

Which prize will she most likely get?

1. \$100 cash
2. Book prize
3. Chocolate package
4. Gift voucher
5. All are equally likely to occur

Question 9

Find the smallest positive integer n for which 1250n is a multiple of 3600.

1. 36
2. 72
3. 3600
4. 7200
5. None of the above

Question 10

Find the last two digits of 201878,

1. 18
2. 24 CG, 32
3. See the source image for option C.
4. 76
5. None of the above

Question 11

The figure on the right is made of 5 cubes. The front gz gO»
and side views of the figure are shown below. BP ‹›
Front View Side View
What is the largest number of cubes in a figure with the following front and
side views?
Front View Side View

1. 16
2. 27
3. 30
4. 33
5. None of the above

Question 12

Royce and Sony were running towards each other at a speed 10 m/s (metres
per second) and 12 m/s respectively. They started running at the same time
and met at point P after 10 minutes. On the next day, they did the same thing
except that Royce increased his speed. As a result, they met 1920 metres from
point P. What is Royce’s new speed in m/s?

1. 12
2. 14
3. 16
4. 18
5. None of the above

Question 13

Usher, Warren, Xavier, Yolanda and Zane went to Lucky Asian food store at
= different times and bought different foods. Usher went inside before the person
who bought a sushi but went inside after the person who bought a ramen.
Xavier is the second person who went inside the store and he did not buy a
sushi. Yolanda went inside before Warren. Zane got a tempura from the store.
The last person who went inside bought kimchi. Who bought dumplings?

1. Usher
2. Warren
3. Xavier
4. Yolanda
5. Zane

Question 14

The sum of some consecutive positive integers is 2018. Find the largest of
these integers.
= A. 1008

1. 1008
2. 1009
3. 1010
4. 1011
5. None of the above

Question 15

How many 2-digit positive integers can be expressed as the difference of two
/ perfect square numbers?

1. 22
2. 45
3. 67
4. 83
5. None of the above

Question 16

An operator A acts on two numbers to give the following results:
7A2=94
3A3=66
5A4=98
11A9= 2018
What is 5 A 7 equal to?

Question 17

How many triangles are there in the figure?

Question 18

Given that 2A + 2B + ZC + ZD + ZE = 1602, find the sum of 5 shaded angles.
a
é B
Seer: | Secs cscer neces eee | eee See ee | Seer oes ee | Serene es
ae
‘ P we al —— Rie ee
‘ | ig
i
a
:
f }
:

}
i acl :
a :
I i = =
Lf S

= oe : =
;
ee ee eS

Question 19

The following bar chart shows the cost of abalone over the first half of the year
2018. The percentage increase in cost remains the same every following
Ss month, Find the average cost of abalone in the first half of year 2018. (Correct
to nearest whole number)

Cost of Abalone

be \$90
ea \$62.50
' : !
January February March April May June

Question 20

Given that x? — 7x +1 = 0, find the value of x* +=.

k
bl ;
Ses SSeS SS ee eee