Tag Archives: Paper 2

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

Con­tinue read­ing

  

Primary 3 Fractions Level 1 Ex 1

P3-Fractions-L1-Ex1

Ans:

1–  4

2–  2

3–  4

4/16 = 1/4

 

4–  1

5–  3

6–  2

7–  1

Total num­ber of daisies –>  2 + 3 + 4 = 9

3/9 = 1/3 

Con­tinue read­ing

  

Primary 6 July Problem Sums 6

P6-July-PSP-Ex 6

Ans:

1–  $800

Frac­tion of money spent on food and shoes –>  1/4 + 1/5 = 9/20

20/20 — 9/20 = 11/20

11u –>  $340 + $100 = $440

1u –> $40

20u –>  $40 ×  20 = $800

 

2–  14 cook­ies

Muffins   :   Cookies

At first  ——>           [   5             :         6   ]  × 2

In the end   ——>    [   2             :        1  ]  × 5

[Make the units of muffins at first and in the end the same]

Muffins   :   Cookies

At first  ———>             10          : 12

In the end  ——->           10          : 5

12u –>  24 cookies

1u –>  2 cookies

5u –>  10 cook­ies left

24 — 10 = 14 cook­ies 

 

3–  Joseph spent more by $2000

3/5 of Terry’s money is equal to 1/3 of Joseph’s money.

[Make the numer­a­tor common]

3/5 of Terry’s is equal to  3/9 of Joseph’s.

Terry   :   Joseph
5         : 9

14u –> $7000

1u –> $500

Amount Terry spent –>  $500 × 5 = $2500

Amount Joseph spent –>  $500 × 9 = $4500

$4500 — $2500 = $2000

Con­tinue read­ing

  

Primary 6 July Problem Sums 5

P6-July-PSP-Ex 5

Ans:

1–  95

[Use trial and error from the largest 2-digit mul­ti­ple of 9]

Great­est pos­si­ble 2-digit mul­ti­ple of 9 –> 99

99 + 5 = 104 (wrong: answer is not 2-digit)

90 + 5 = 95 (correct)

 

2–  100 grey squares and + 99 white tiles

Num­ber of grey tiles –> Pat­tern Num­ber × 2

50 × 2 = 100 grey tiles

Num­ber of white tiles –>  Num­ber of grey tiles — 1

100 — 1 = 99 white tiles

 

3–  108 teach­ers

Pupils  –>                      Boys  :  Girls
4     : 5

5u –> 2400

1u –> 280

9u –>  280 × 9 = 4320 children

Teach­ers  :  Pupils
1          : 40

40u –> 4320

1u –>  108 teach­ers

 

4–  14 years old

Nicholas’ age now –>  35 — 8 = 27 years old

Timothy’s age now –>  1/3 × 27 = 9 years old

9 + 5 = 14 years old

Con­tinue read­ing

  

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 

Con­tinue read­ing

  

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

 

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

Con­tinue read­ing

  

Primary 6 SA1 Revision 9

P6-SA1-Ex 9

Ans:

1–  4 cm

Length of square –>  12 cm

12 ÷ 2 = 6 cm ( length of square B)

Are of square B –>  144 ÷ 6 = 24 cm²

24 ÷ 6 = 4 cm

 

2–  3.43 p.m.

135 ÷ 75 = 1  4/5 h

1  4/5 h + 1/4 h = 2  1/20 h

2  1/20 h = 2 h 3 min

2 h 3 min after 1.40 p.m. –>  3.43 p.m.

 

3–  343 cm³ 

Area of 1 sur­face of the cube –>  294 ÷ 6 = 49 cm²

Length of cube –>  7 cm

Vol­ume –>  7 × 7 × 7 = 343 cm³

 

4–  11%

$440 — $395 = $45

45/395 × 100 ≈ 11%

Con­tinue read­ing

  

Primary 4 SA1 Revision 4

P4-SA1-Ex 4

Ans:

1–  3

2–  4

3–  3

4–  4

5–  1

6–  2

Con­tinue read­ing

  

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

Con­tinue read­ing