Question 1

In 6.015, what is the place value of the digit 0?

Accepted Answer

(3) tenths. In the number 6.015, the digit '0' is immediately to the right of the decimal point, which is the tenths place.

Question 2

Find the value of 6 + 18 ÷ 3 × 2 - 9.

Accepted Answer

(2) 9. Following the order of operations (BODMAS/PEMDAS):
1. Division: 18 ÷ 3 = 6
2. Multiplication: 6 × 2 = 12
3. Addition and Subtraction from left to right: 6 + 12 - 9 = 18 - 9 = 9.

Question 3

Ahmad has $2 and Ben has $4. Which one of the following statements is incorrect?

Accepted Answer

(1) The ratio of Ahmad's money to Ben's money is 2: 1.. Ahmad's money = $2, Ben's money = $4.
Ratio of Ahmad's money to Ben's money = $2 : $4 = 1 : 2.
Ratio of Ben's money to Ahmad's money = $4 : $2 = 2 : 1.
Statement (1) says Ahmad : Ben is 2 : 1, which is incorrect. Statements (2), (3), and (4) are correct (4:2 simplifies to 2:1).

Question 4

Express 108 min in hours.

Accepted Answer

(4) 1 4/5 h. There are 60 minutes in 1 hour. So, 108 min = 108/60 hours.
108/60 = 1 and 48/60 hours.
Simplifying the fraction 48/60: Divide both numerator and denominator by 12, which gives 4/5.
So, 108 min = 1 4/5 hours.

Question 5

Which one of the following pairs is the base and height of Triangle ABC?

Accepted Answer

(2) AC, BD. The height of a triangle is the perpendicular distance from a vertex to the opposite side (the base). In the given diagram, the line segment BD is drawn from vertex B perpendicular to side AC. Therefore, AC is the base and BD is the corresponding height.

Question 6

Find the product of all the factors of 4.

Accepted Answer

(2) 8. The factors of 4 are the numbers that divide 4 exactly. These are 1, 2, and 4.
The product of these factors is 1 × 2 × 4 = 8.

Question 7

What is the value of ∠a in the rhombus?

Accepted Answer

(3) 92°. In a rhombus, diagonals bisect the angles. The given angle of 44° is half of one of the interior angles. So, one interior angle of the rhombus is 44° × 2 = 88°.
Adjacent angles in a rhombus are supplementary (sum to 180°). Therefore, angle 'a' (which is adjacent to the 88° angle) is 180° - 88° = 92°.

Question 8

The table shows the amount of play time Eisha has for three days. What is Eisha's average amount of play time for the three days?

Accepted Answer

(2) 2 h. Total play time = 0 hours (Day 1) + 2 hours (Day 2) + 4 hours (Day 3) = 6 hours.
Average play time = Total play time / Number of days = 6 hours / 3 days = 2 hours.

Question 9

The table shows the parking rates at a car park. Carol parked her car at the car park from 8.30 a.m. to 10.30 a.m. How much did she pay?

Accepted Answer

(2) $4.50. Duration of parking = 10:30 a.m. - 8:30 a.m. = 2 hours.
Cost for the 1st hour = $2.50.
Remaining time = 2 hours - 1 hour = 1 hour = 60 minutes.
Cost for every additional 15 minutes = $0.50.
Number of 15-minute blocks in the remaining 60 minutes = 60 / 15 = 4 blocks.
Cost for additional time = 4 × $0.50 = $2.00.
Total cost = $2.50 (for 1st hour) + $2.00 (for additional time) = $4.50.

Question 10

In the morning, Dawn started doing her homework at the time shown below. She completed the work before noon. How many ¼ turns did the minute hand of the clock go through?

Accepted Answer

(4) 6. The first clock shows 11:15 a.m. (minute hand at 3). The second clock shows 1:45 p.m. (minute hand at 9). However, the question states she completed the work 'before noon'. This indicates a discrepancy in the problem statement or images. If we assume the clocks were intended to be 11:15 a.m. and 12:45 p.m. (to be after noon but still using the given minute hand positions), the duration is 1 hour 30 minutes = 90 minutes. Since 1/4 turn is 15 minutes, 90 minutes = 90/15 = 6 quarter turns. If we assume the clocks are 11:15 and 11:45 (30 minutes), it would be 2 quarter turns. The answer key points to 6, which aligns with 90 minutes duration from 11:15 to 12:45. The 'before noon' condition is problematic if taken strictly.

Question 11

0.25 of a number is 40. What is 80% of the number?

Accepted Answer

(3) 128. 0.25 is equivalent to 1/4. If 1/4 of a number is 40, then the full number is 40 × 4 = 160.
80% of the number = 0.80 × 160.
0.80 × 160 = 8/10 × 160 = 8 × 16 = 128.

Question 12

An object was moved South and then in the North-West direction. It ended at Point X. Where was the start point of the object?

Accepted Answer

(1) A. To find the starting point, we reverse the movements from the end point X.
1. The last movement was North-West. To reverse this, move South-East from X. Moving one cell South and one cell East from X leads to the cell below and to the right of X.
2. The first movement was South. To reverse this, move North from the current position (the cell below and right of X). Moving one cell North from there leads to Point A.
Thus, the object started at Point A.

Question 13

Hela paid for an eraser that cost k cents with a two-dollar note. How much change did she receive?

Accepted Answer

(2) $(2-k/100). The payment was a two-dollar note, which is $2.
The cost of the eraser is k cents. To convert cents to dollars, divide by 100. So, k cents = $k/100.
Change received = Amount paid - Cost of eraser = $2 - $k/100 = $(2 - k/100).

Question 14

There were 12 chairs in each of the 15 rows in a hall. 60 more chairs were brought into the hall. All the chairs were then rearranged equally into 20 rows. Which one of the following shows the correct way to find the number of chairs in each row?

Accepted Answer

(4) (12 × 15 + 60) ÷ 20. First, calculate the initial total number of chairs: 12 chairs/row × 15 rows = 12 × 15.
Then, add the 60 more chairs: (12 × 15) + 60.
Finally, divide the total number of chairs by the new number of rows (20) to find chairs per row: ((12 × 15) + 60) ÷ 20.
Option (4) correctly represents this calculation.

Question 15

Which of the following views is incorrect?

Accepted Answer

(1). Let's analyze the 3D block: It has a base of three cubes in a row (front). The leftmost cube of this row has two more cubes stacked on top (total 3 high). The middle cube has one more cube stacked on top (total 2 high). The rightmost cube has no more stacked (total 1 high). Additionally, there is one cube directly behind the leftmost cube of the front row (making it a 4-block base if viewed from top).

Coordinates (relative to front-left-bottom (0,0,0)): 
(0,0,0), (0,0,1), (0,0,2) (left stack, 3 high)
(1,0,0), (1,0,1) (middle stack, 2 high)
(2,0,0) (right stack, 1 high)
(0,1,0) (back-left block, 1 high)

1.  **Top View:** Looking from above, the occupied (x,y) positions are (0,0), (1,0), (2,0), and (0,1). This forms a shape like:
    [X][X][X]
    [X][ ][ ]
    This is a 4-square shape. Option (1) shows a 3-square L-shape ([X][X] on top row, [X][ ] on bottom row). Therefore, Option (1) is **incorrect**.

2.  **Front View:** Looking from the front (along the y-axis). Heights from left to right are: 
    x=0: max(height at (0,0), height at (0,1)) = max(3,1) = 3
    x=1: height at (1,0) = 2
    x=2: height at (2,0) = 1
    So, the front view is stacks of (3, 2, 1). Option (3) shows this correctly.

Since Option (1) is demonstrably incorrect, and the question asks for the *incorrect* view, (1) is the correct choice. (Options 2 and 4 represent side views. Their correctness would depend on the specific viewing direction, but as option 1 is clearly incorrect based on the top view of the figure, it's the intended answer).

P6 Mathematics SA1 2021 — Tao Nan

Related Sparks

Related reads

P6 Mathematics SA1 2021 — Tao Nan

Related papers

Related Sparks

Related reads