Primary 6 Circles Level 3 Ex 1

P6-Circles-L3-Ex 1

Ans:

1–  1152 m

Perime­ter of each semi­cir­cle–>  1/2 × 22/7 × 28 = 44 m

2 semi­cir­cles –>  44 × 2 = 88 m

Total perime­ter of track –>  100 + 100 + 88 = 288 m

4 rounds –>  288 m × 4 = 1152 m

 

2–  Area ->  87.5 cm² , Perime­ter –>  39 cm
Area of square –>  7 cm × 7 cm = 49 cm²

Area of quad­rant –>  1/4 ×22/7 × 7 × 7 = 38.5 cm²

Area of fig­ure –>  49 cm² + 38.5 cm² = 87.5 cm²

Perime­ter of quad­rant –>  1/4 × 22/7 × 14 cm = 11 cm

Perime­ter of fig­ure –>  11 cm + 4 × 7 cm = 39 cm

 

3–  34 cir­cles
Qn 3

 

 

 

 

 

Length ->  69 cm ÷ 4 ≈ 17

Breadth -> 9 cm÷ 4 ≈ 2

17 × 2 = 34 cir­cles 

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Primary 5 July Problem Sums 1

P5-July-PSP-Ex 1

Ans:

1–  $2425
Qn 1

1u –>  $1600 + $750 = $2350

$2350 + $750 = $2425

 

2–  29/45

Amount Diane saves -> $1800 — $640 = $1160

1160/1800 = 29/45

 

3–  4  1/2 kg

Mass of apples when the bas­ket is com­pleted filled –>  8 kg — 1 kg = 7 kg

Mass of apples when bas­ket is 1/2 filled –>  7 kg ÷ 2 = 3  1/2 kg

3  1/2 + 1  = 4  1/2 kg

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Primary 4 July Problem Sums 1

P4-July-PSP-Ex 1

Ans:

1–  63 sweets

2–  $90

Qn 2

2u –>  $75 — $45 = $30
1u –> $15

$15 + $75 = $90

 

3–  96 cook­ies
Qn 3

5u –>  80 cookies

1u –>  16 cookies

6u –>  16 cook­ies × 6 = 96 cook­ies

 

4–  $68
Qn 4

3u –>  $48 + $12 = $60

1u –> $20

$48 + $28 = $68

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Primary 3 Money Level 1 Ex 1

P3-Money-L1-Ex 1

Ans:

1–  1

2–  1

$100 — $ 4 + $96  (amount spent on the comics)

$96 ÷ $8 = 12 comics

 

3–  1

4–  3 Con­tinue read­ing

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Primary 6 Speed Level 2 Ex 1

P6-Speed-L2-Ex 1

Ans:

1–  52 km/h

11.25 a.m. to 2.40 p.m. –>  3 h 15 min = 3  1/4 h

169 km ÷ 3  1/4 h = 52 km/h

 

2–  2.4 m/s

Dis­tance between 1st floor and 25th floor –>  24 × 4 = 96 m

96 m ÷ 40 sec = 2.4 m/s

 

3–  60 km/h

Time taken 180 km ÷ 54 km/h = 3  1/3 h = 3 h 20 min

New time –>  3 h 20 min — 20 min = 3 h

180 km ÷ 3 h = 60 km/h

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Primary 5 Decimals Level 2 Ex 5

P5-Decimals-L2-Ex5

Ans:

1–  4/25

2–  tenths

3–  2040 g

2.04 × 1000 = 2040 g

 

4–  23.9 cm

5–  40.6 kg  Con­tinue read­ing

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Primary 4 June Problem Sums 1

P4-Jun-PSP-Ex1

Ans:

1–  1120 stick­ers
Qn1

9u –>  1260 stickers

1u –>  140 stickers

8u –>  140 × 8 = 1120 stick­ers

 

2–  $28 125

Total num­ber of TV sets sold –>  15 × 5 = 75

$375 × 75 = $28 125 

 

3–  a ->  4 ostriches  ,   b ->  76 more legs

Qn3

 

84 — 8 = 76 more legs   (b)

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Primary 3 June Review 1

P3-Jun-Review 1

Ans:

1–  2

2–  3

3–  3

4–  1

5–  2

6–  4

Num­ber of cook­ies sold on Tue –>  124 + 12 = 136

124 + 136 = 260 cook­ies 

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Primary 6 June Problem Sums 6

P6-PSP-Jun-Ex 6

Ans:

1–  60 stamps
Qn 1

4u –>  26 + 14 = 40

1u –>  40 ÷ 4 = 10 stamps

6u –> 10 × 6 = 60 stamps

 

2–  6.05 m

Total length of rope Edmond and Mandy had ->  24.6 m + 32.5 m = 57.1 m

57.1 m — 4.2 m = 52.9 m

Length of rope Mandy had in the end –>  52.9 m ÷ 2 = 26.45 m

32.5 m — 26.45 m = 6.05 m

 

3–  13 big water­mel­ons and 5 small watermelons

Assume all 18 water­mel­ons were small –>  18 × $3 = $54

$67 — $54 = $13 (excess)

Since each big water­melon cost $1 more–>  $13 ÷ $1 = 13 big watermelons

18 — 13 = 5 small watermelons

 

4–  See below
Qn 4

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Primary 5 May Problem Sums 2

P5-May-PSP-Ex 2

Ans:

1–  48 mar­bles

[Inter­nal difference/ Con­stant Total]

1u + 7u = 8u (total)

8u ÷ 2 = 4u

4u — 1u = 3u (units Casper received from Zachary)

3u –> 18

1u –> 6

8u –>  6 × 8 = 48 mar­bles

 

2–  $280

Num­ber of months Nikki took to save $7000 –>  $7000 ÷ $140 = 50 months

Num­ber of Months Stephanie took to save $7000 –>  50 — 25 = 25 months

$7000 ÷ 25 = $280

 

3–  732 fewer points

Qn 3

5u –>  1277 — (158 × 4)  = 645

1u –>  645 ÷ 5 = 129

(158 × 3) + (129 × 2) = 732 fewer points

 

4–  $90

Amount of money they had in the end–>  $150 — $20 — $50 = $80

$80 ÷ 2 = $40

$40 + $50 = $90

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