Skip to content / Đến nội dung
ThichHocToan.com

SASMO 2020 Grade 6

Question 1

Platform scoring: start at 0; Q1–15: 2 points each; Q16–25: 4 each; wrong or blank: 0; maximum 70. Official SASMO reference scoring is separate: start at 15, Section A +2/−1/0 and Section B +4/0/0 for correct/wrong/blank, maximum 85.

Find the value of $2020\times2020-2019\times2021$.
  1. 2020
  2. 4040
  3. 1
  4. 2
  5. None of the above

Question 2

What is the next number in the following pattern? $1,2,6,15,31,56,\ldots$

Use the intended elementary number pattern; a finite sequence can support other rules.
  1. 92
  2. 81
  3. 105
  4. 78
  5. None of the above

Question 3

In a supermarket, chicken nuggets are available only in packs of either 3 or 7 nuggets. For example, you cannot purchase exactly 2, 5 or 8 nuggets. What is the largest number of chicken nuggets that one cannot purchase?
  1. 231
  2. 721
  3. 23
  4. 13
  5. None of the above

Question 4

In the diagram, the unshaded area is made of 4 semicircles touching at the centre of the large circle. If the diameter of the large circle is 28 cm, find the area of the shaded region. Use $\pi=\frac{22}{7}$.

Question illustration
  1. $616\text{ cm}^2$
  2. $462\text{ cm}^2$
  3. $308\text{ cm}^2$
  4. $154\text{ cm}^2$
  5. None of the above

Question 5

James has tiles of size 3 cm × 7 cm. He wants to put them on a floor of size 23 cm × 10 cm. What is the largest number of tiles he can put without overlapping or breaking any tiles?

Tiles may be rotated but must lie completely inside the rectangular floor.
  1. 10
  2. 9
  3. 8
  4. 7
  5. None of the above

Question 6

The following bar chart shows the responses made by SASMO Primary 6 students in a multiple-choice question. All the horizontal lines are equally spaced. Each student selected one of the possible choices, and the correct answer is C. Find the percentage of students who answered this question correctly.

Question illustration
  1. 25%
  2. 16%
  3. 24%
  4. 20%
  5. None of the above

Question 7

Working alone, Ryan can dig a 5 m by 5 m by 5 m hole in six hours. Castel can dig a 10 m by 10 m by 5 m hole in twelve hours. How many hours would it take them to dig a 5 m by 5 m by 5 m hole if they worked together?

Assume each person digs at a constant rate and their rates add when working together.
  1. 4
  2. 1
  3. 2
  4. 3
  5. None of the above

Question 8

The five-digit number $\overline{A549B}$ is divisible by 45. Find the value of $A+B$.
  1. 0
  2. 9
  3. 18
  4. 27
  5. None of the above

Question 9

Which cube below has a top view the same as the clock shown?

Question illustration

Question illustration

Compare the top views up to rotation, not reflection. The labelled choices A–E are shown in the original diagram.
  1. A
  2. B
  3. C
  4. D
  5. E

Question 10

Stacy bought a pack of M&M chips. After she ate some, the ratio of the number of chips she ate to the number remaining in the pack was 3 : 5. If she eats 50 chips more, the new ratio will be 7 : 5. How many M&M chips were there in the pack when Stacy bought it?
  1. 10
  2. 150
  3. 240
  4. 140
  5. None of the above

Question 11

The minute hand of a certain clock is 3 times as long as the hour hand. In 24 hours, the tips of the hour and minute hands travel $1036\pi$ cm in total. How long is the hour hand? Use $\pi=\frac{22}{7}$.
  1. 7 cm
  2. 21 cm
  3. 14 cm
  4. 7.5 cm
  5. None of the above

Question 12

In mathematics, the product of the first $n$ positive integers is written as $n!=n\times(n-1)\times\cdots\times1$. For example, $2!=2\times1$ and $7!=7\times6\times5\times4\times3\times2\times1$. How many consecutive digits 0 are at the end of $8!+9!$?
  1. 0
  2. 2
  3. 1
  4. 3
  5. None of the above

Question 13

Four identical rectangles are placed side by side on a 28 cm by 20 cm rectangular piece of paper in two ways, as shown in Figures A and B. What is the difference between the perimeters of the shaded regions in Figures A and B?

Question illustration

For Figure B, add the perimeters of both disconnected shaded pieces.
  1. 96 cm
  2. 80 cm
  3. 32 cm
  4. 16 cm
  5. None of the above

Question 14

Hailey, Lydia, Julia, Asher and Charles are Primary 4 or 6 students. They study in either Bright Primary School or Light Primary School.
- Lydia and Charles are in the same grade.
- Julia and Asher study at different levels.
- Three students study in Primary 4 and the other two in Primary 6.
- Asher and Charles are from different schools.
- Hailey and Julia go to the same school.
- Three students go to Bright Primary School and the other two to Light Primary School.

If one of them is a Primary 6 student from Light Primary School, who is that person?
  1. Hailey
  2. Lydia
  3. Julia
  4. Asher
  5. Charles

Question 15

At which of the following times is the hour hand closest to the minute hand of a clock?
  1. 9:47
  2. 9:48
  3. 9:49
  4. 9:50
  5. 9:51

Question 16

Find the last digit of the product of twenty factors equal to 2 and twenty-four factors equal to 3: $\underbrace{2\times2\times\cdots\times2}_{20\text{ factors}}\times\underbrace{3\times3\times\cdots\times3}_{24\text{ factors}}$.

Input: enter the requested whole-number answer without units. Leading zeroes from the paper grid may be omitted.

Question 17

How many triangles are there in the figure below?

Question illustration

Count triangles of every size whose three full sides are drawn. The lines shown meeting at the central junction are intended to meet at one point.

Input: enter the requested whole-number answer without units. Leading zeroes from the paper grid may be omitted.

Question 18

Find the value of $\left(\frac1{20\times25}+\frac1{25\times30}+\frac1{30\times35}+\cdots+\frac1{2015\times2020}\right)\times2020$.

Input: enter the requested whole-number answer without units. Leading zeroes from the paper grid may be omitted.

Question 19

The number of apples in a basket is $\frac45$ of the number of oranges. The ratio of pears to apples is $3:8$. The rest of the fruits are bananas, and 20% of all the fruits in the basket are oranges. The number of bananas is 48 more than the total number of apples, oranges and pears. How many fruits are there in the basket?

Input: enter the requested whole-number answer without units. Leading zeroes from the paper grid may be omitted.

Question 20

The number of digits used to number the pages of a book is twice the number of pages of the book. If the number of pages is a three-digit number, how many pages does the book have?

Pages are numbered consecutively from 1, with no leading zeroes.

Input: enter the requested whole-number answer without units. Leading zeroes from the paper grid may be omitted.