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ITMC 2019 Grade 6 National Preliminary set01

Question 1

Printed positive marks are preserved per question. The source uses different blank-answer and incorrect-answer rules by section, including an optional bonus penalty; the import does not reproduce that complete official scoring scheme.

How much is $0.1\times0.2\times0.3\times0.4\times0.5$ less than $0.2019$?
  1. 0.2007
  2. 0.2107
  3. 0.0217
  4. 0.2117
  5. 0.0107

Question 2

Given that $0.2$ times $A$, plus $A$, equals $A+\frac45$, find $A$.
  1. $5\frac14$
  2. 4
  3. 3
  4. $\frac45$
  5. $\frac34$

Question 3

Let $A(x)=x+\frac15$. For example, $A(1)=1+\frac15=\frac65$ and $A(5)=5+\frac15=\frac{26}5$. Determine $A(1)+A(2)+A(3)+\cdots+A(10)$.
  1. $\frac{216}5$
  2. $\frac{246}5$
  3. $\frac{276}5$
  4. 57
  5. 66

Question 4

In the adjoining figure, what is the area of the shaded region in square units?

Question illustration
  1. 26
  2. 18
  3. 16
  4. 12.5
  5. 9.5

Question 5

Consider this process. Step 1: draw a square, divide it into four equal parts as shown, and paint one part red. Step 2: repeat step 1 on the red part and paint the chosen part yellow. Step 3: repeat step 1 on the yellow part and paint the chosen part green. Step 4: repeat step 1 on the green part and paint the chosen part blue. What fraction of the whole square is blue?

Question illustration
  1. $\frac1{512}$
  2. $\frac1{256}$
  3. $\frac1{128}$
  4. $\frac1{64}$
  5. $\frac1{32}$

Question 6

An envelope has size $10.8$ cm $\times16.5$ cm. In Fig. 1 it is opened to measure its size; in Fig. 2 it is closed. What is the area of the unshaded region in Fig. 2, in square centimetres?

Question illustration
  1. 84.15
  2. 123.045
  3. 130.025
  4. 131.175
  5. 133.065

Question 7

A bakery has 7 chefs who make 100 pieces of cake in 8 hours. Today 2 chefs cannot come, so the remaining chefs make 100 pieces and finish in $a$ hours $b$ minutes. Find $a+b$.
  1. 23
  2. 24
  3. 25
  4. 26
  5. 28

Question 8

$N$ is the least positive integer leaving remainder 2 when divided by 4, remainder 5 when divided by 7, and remainder 9 when divided by 11. What is the remainder when $4\times7\times11$ is divided by $N$?
  1. 1
  2. 2
  3. 7
  4. 11
  5. 15

Question 9

A number pattern is $1,1,2,1,2,3,1,2,3,4,1,2,3,4,5,1,\ldots$. What number is its 77th term?
  1. 13
  2. 12
  3. 11
  4. 9
  5. 8

Question 10

A student spent all 300 baht from Monday to Friday. The pie chart shows the daily expenses. How much did the student spend on Friday?

Question illustration
  1. 80
  2. 85
  3. 90
  4. 92
  5. 95

Question 11

There are four bags of number cards, one number per card. Bag 1 contains 1–10; bag 2 contains 12–20; bag 3 contains 23–30; bag 4 contains 24–35. Each bag has one card for each integer in its range, with no repeated number. From which bag should a student draw one card at random to have the greatest chance of an even number?
  1. Bag 1
  2. Bag 2
  3. Bag 3
  4. Bag 4
  5. Bag 1 or 2 or 3 or 4

Question 12

The table shows the number of students in each grade of a primary school. Let $a$ be the grade 5 enrolment, $b$ the grade 6 enrolment, and $c$ the total. Grade 6 has 2 fewer students than grade 5, and the average enrolment per grade is 249. Find $a+b+c$.

Question illustration
  1. 1925
  2. 1935
  3. 1956
  4. 1994
  5. 2019

Question 13

Find $12131415\times1918171615$.
  1. 23,270,135,902,785,295
  2. 23,270,135,902,785,275
  3. 23,270,135,902,785,245
  4. 23,270,135,902,785,235
  5. 23,270,135,902,785,225

Question 14

The fraction $\frac14$ is the decimal $0.25$, whose first digit after the decimal point is 2 and second digit is 5. When $\frac{2019}{2562}$ is written as a decimal, what is its fourth digit after the decimal point?
  1. 7
  2. 5
  3. 0
  4. 3
  5. 8

Question 15

Uncle George has 50 chickens, ducks and geese altogether. There are 19 more chickens than ducks. Each day a chicken gives 3 eggs, a duck 2 eggs and a goose 1 egg. Today there are 115 eggs in total. How many ducks does he have?
  1. 5
  2. 6
  3. 7
  4. 8
  5. 9

Question 16

Rectangle $ABCD$ contains seven equal shaded circles, tangent as shown. Each circle has radius 7 cm. Find the unshaded area in square centimetres, using $\pi=\frac{22}7$.

Question illustration
  1. 1644
  2. 1754
  3. 1745
  4. 1862
  5. 1884

Question 17

Joe has the two-storey rectangular container shown. A notebook is 12 cm wide, 17 cm long and 1 cm thick. A book is 12 cm wide, 17 cm long and 2 cm thick. He keeps notebooks in the top storey and books in the bottom storey. What are the greatest possible numbers of notebooks and books that fit?

Question illustration
  1. 72 notebooks and 84 books
  2. 74 notebooks and 84 books
  3. 76 notebooks and 89 books
  4. 80 notebooks and 92 books
  5. 84 notebooks and 90 books

Question 18

Quadrilateral $ABCD$ has $\angle ABC=90^\circ$, $\angle BCD=150^\circ$, and $AB=BC=CD$. Find $\angle CDA$.
  1. $15^\circ$
  2. $22.5^\circ$
  3. $30^\circ$
  4. $45^\circ$
  5. $60^\circ$

Question 19

A pattern of fractions is $\frac{11}{13},\frac{13}{24},\frac{15}{56},\frac{17}{72},\ldots,\frac ab$, where $\frac ab$ is the 15th term. It can be written as $\frac1x+\frac1y$. Find $(a+b)-(x+y)$.
  1. 220
  2. 240
  3. 320
  4. 380
  5. 420

Question 20

Find the sum of 3% of 14% of 25 kilometres and 5% of 7% of 70 metres.
  1. 103,725 millimetres
  2. 104,025 millimetres
  3. 104,135 millimetres
  4. 104,155 millimetres
  5. 105,245 millimetres