Category Archives: Primary 5

Primary 5 October Problem Sums 5

P5-PSP-Oct-Ex5

Ans:

1–  $6588

2–  2400 cm³

Amount of water at first –>  4/5 × 30 cm × 20 cm × 30 cm = 14 400 cm³

Amount of water in the end –>  2/3 × 30 cm × 20 cm × 30 cm = 12 000 cm³

14 400 cm³ — 12 000 cm³ = 2400 cm³

 

3–  38 mar­bles

Qn 3

2u –>  96 — 60 = 36

Barry –>  36 ÷ 2 = 18 marbles

Joe –>  60 — 18 = 42 marbles

Tom –>  18 × 3 = 54 marbles

Total –> 54 + 42 + 18= 114 marbles

114 ÷ 3 = 38 mar­bles

 

4–  Cup Y —  160 ml    ,   Cup Z —  60 ml

Y   :   Z
8   : 3

8u + 3 = 11u

11u ÷ 2 = 5.5u

8u — 5.5u = 2.5u

2.5u –>  50 ml

1u –>  20 ml

Cup Y –>  20 ml × 8u = 160 ml

Cup Z –>  20 ml × 3 = 60 ml

 

5–  $651.80

Qn 5

2u –>  $1505 — $201.40 = $1303.60

$1303.60 ÷ 2 = $651.80

 

6–  $15.50

Qn 6

 

2u–  $108 — $71 = $37

1u —  $18.50

Megan –> $18.50 × 3 = $55.50

$71 — $55.50 = $15.50

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Primary 5 Volume Level 3 Ex 2

P5-Volume-L3-Ex 2

Ans:

1–  32 768 cm³ 32.768 l

3/4 — 5/8 = 1/8 poured out

1/8 × 64 cm × 64 cm × 64 cm = 32 768 cm³ / 32.768 l

 

2–  16 800 cm³16.8 l

3–  300 ml

4/5 — 1/2 = 3/10 filled

3/10 × 10 cm × 10 cm × 10 cm = 300 cm³ = 300 ml

 

4–  720 ml

8 cm — 5 cm = 3 cm

Amount of water poured out –>  40 cm × 30 cm × 3 cm = 3600 cm³

3600 cm³ ÷ 5 = 720 cm³ = 720 ml

 

5–  25 cm

Length   :   Breadth
4        : 1

4u — 1u = 3u

3u –>  6 cm

1u –>  2 cm –>  breadth

Length –>  2 cm × 4 = 8 cm

Base area –>  2 cm × 8 cm = 16 cm²

400 ÷ 16 = 25 cm

 

6–  17.5 cm

1600 cm³ ÷ 640 cm² = 2.5 cm

2.5 cm + 15 cm = 17.5 cm

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Primary 5 September Review 1

P5-Sep-Review 1

Ans:

1–  3

2–  2

3–  3

4–  4

7u –> $756

1u –> $108

10u–>  $108 × 10 = $1080

 

5–  1

6–  3

80% –> $1800

1% –>  $22.50

100% –>  $22.50 × 100 =  $2250

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Primary 5 Average Level 3 Ex 4

P5-Average-L3-Ex4

Ans:

1–  432 more stamps

Total num­ber of stamps Jamie and Patrick had ->  360 × 2 = 720

Patrick -> 1u

Jamie -> 4u

5u –>  720 stamps

1u –>  144 stamps

4u — 1u = 3u

3 × 144 = 432 more stamps

 

2–  71.5 kg

Total mass of 3 boys if they weigh as much as Derek –>  75 × 3 + 12 + 9 = 246 kg

Derek’s mass  –>  246 kg ÷ 3 = 82 kg

Joe’s actual mass ->    82 kg — 12 kg = 70 kg

Ron’s actual mass ->  82 kg — 9 kg = 73 kg

Aver­age mass of Joe and Ron –>  (70 + 73) ÷ 2 =  71.5 kg

3–  5.8 m

Total mass of the pole, plank and rod –>  4.8 m × 3 = 14.4 m

Rod –> 1u

Pole –> 2u

Plank –>  2u + 0.4 m

5u +  0.4 m ->  14.4 m

5u –>  14.4 m — 0.4 m = 14 m

Rod  –>  14 m ÷ 5 = 2.8 m

Pole –>  2.8 m × 2 = 5.6 m

Plank –>  2.8 m × 2 + 0.4 = 6 m

Aver­age length of pole and plank –>  (5.6 m + 6 m ) ÷ 2 = 5.8 m

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Primary 5 July Review 2

P5-Jul-Review 2

Ans:

1–  2

2–  3

3–  3

4–  3

5–  1

150 : 3000
–>   1   : 20

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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 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

  

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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Primary 5 SA1 Revision 4

P5-SA1-Ex 4

Ans:

1–  3

2–  3

3–  2

4–  1

5–  4

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Primary 5 SA1 Revision 3

P5-SA1-Ex 3

Ans:

1–  4 : 3

Dar­ryl     :     Peter
2          : 5

2/5 × 5u = 2u  (what Peter gave to Darryl)

In the end:    Dar­ryl –>  2u + 2u = 4u

Peter –>  5u –2u = 3u

Dar­ryl     :     Peter
 4         : 3

 

2–  20 kg

Amount of money Laura had –>  $4 × 23 = $92

$92 ÷ $4.60 = 20 kg

 

3–  7200 stamps

36 000 ÷ 5 = 7200 stamps

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