Tag Archives: Primary 6

Primary 6 Prelims Revision 6

P6-Prelims-Ex 6

Ans:

1–  $1225

18% = 9/50

90% = 9/10

There­fore,

Bran­don   :   Charles
50        :     10
5          : 1

6u –> $1470

1u –> $245

$245 × 5u = $1225

 

2–  9/10 h

Time taken to fill 1/9 of the tank –>  2/5 ÷ 4 = 1/10 h

1/10 h × 9 = 9/10 h

 

3–  8 pen­tagons

3 × 5 = 15 match­sticks for the 3 extra pentagons

60 — 15 = 45 match­sticks (The num­ber of squares and pen­tagons are now the same)

Num­ber of match­sticks needed to make 1 square and 1 pen­ta­gon -> 4 + 5
= 9

45/9 = 5

5 + 3 = 8 pen­tagons

 

4–  10 hours

55 min = 11/12 h

11/12 h + 3/4 h = 1   2/3 h

5  1/2 h ÷ 11/12 h = 6 sets

6 × 1   2/3 h = 10 hours

 

5–  $40

85% — 55% = 30%

30% –> $12

100% –>  12/30 × 100 = $40

Con­tinue read­ing

  

Primary 6 Prelims Revision 3

P6-Prelims-Ex 3

Ans:

1–  3 : 12 : 17

2–  4.95 cm

Length of the tank –>  180 cm³ ÷ 12 edges = 15 cm

33/100 × 15% = 4.95 cm

 

3–  100 balls

Total units of balls –>  5u + 4u = 9u

Units of balls in each bag in the end –>  9u/2 = 4.5u

5u — 4.5u = 0.5u —>  10 balls

1u –>  10 × 2 = 20 balls

20 × 5u = 100 balls

 

4–  540 km

5–  $24

1 blouse –> 1u

1 pair of jeans –>  1u + $12

3 pairs of jeans + 4 blouses –>  (1u + $12) × 3 + 4u = 7u + $36

7u + $36 -> $204

7u –>  $204 — $36 = $168

1u –>  $24

 

6–  891 beads

Red : Blue + Green
4   : 5

Blue : Green
3    :    8     –> 11u

Adjust the units for the blue and green beads such that they are the same in both cases.

Com­mon mul­ti­ple of 5 and 11 is 55u

There­fore,

Red  :  Blue + Green
44   : 55

Blue  :  Green
15   : 40

Red  :  Blue  :  Green
44 :    15   : 40

44u — 40u = 4u –>  36 beads

1u –>  9 beads

44u + 55u = 99u —->  9 beads × 99 = 891 beads

Con­tinue read­ing

  

Primary 6 SA1 Revision 12

P6-SA1-Ex 12

Ans:

1–  175

2–  $43.50

70% of the price –>  $101.50

30% –>  $101.50/70 × 30 = $43.50

 

3–  (3+ 6) kg

Alan’s mass ->  (+ 3) kg

Nicholas’ mass ->  (m + 3) — 2 = (+ 1) kg

Brett’s mass ->  (+ 1) + 1 = (+ 2) kg

(m + 3) + (+ 1) + (+ 2) = (3+ 6) kg

 

4–  195 km

1  1/2 h× 80 km/h = 120 km

45/60 h × 100 km/h = 75 kg

120 km + 75 km = 195 km

 

5–  $6441.60

Earn­ings in Jan­u­ary –>  122/100 × $6000 = $7320

Earn­ings in Feb­ru­ary –>  88/100 × $7320 = $6441.60

 

6–  30 peo­ple

Frac­tion of men  –>  30/100 = 3/10 = 9/30

Frac­tion of men if 10 women alighted –>  45/100 = 9/20

Women –>  30u — 9u = 21u

20u — 9u = 11u

10u –>  10 women

30 u –>  30 people

Con­tinue read­ing

  

Primary 6 SA1 Revision 11

P6-SA1-Ex 11

Ans:

1–  22

2– $100.00

3–  15 000.02 m

4–  7/8 ,  5/6 ,   1/2 , 1/4

5–  5 p.m.

2 h 15 min before 11.45 a.m. –>  9.30 a.m.

7 h 30 min after 9.30 a.m. –>  5 p.m.

Con­tinue read­ing

  

Primary 6 SA1 Revision 10

P6-SA1-Ex 10

Ans:

1–  3

2–  3

3–  4

2u –> 18 cm

1u –>  9 cm

Length –>  9 cm × 3u = 27 cm

Perime­ter –>  (18 + 27) cm × 2 = 90 cm

 

4–  2

5–  2

6–  3

Frac­tion of remain­ing cake –> 5/6

5/6 ÷ 1/12 = 10 pupils

Con­tinue read­ing

  

Primary 6 April Problem Sums 5

P6-PSP-Apr-Ex 5

Ans:

1–  30 m

Spaces between 100 trees –> 99

Dis­tance between each tree –> 297 m ÷ 99 = 3 m

3 m × 10 spaces = 30 m

 

2–  28 pupils

Num­ber of pupils who passed one or both sub­jects –> 40 — 2 = 38

30 + 36 = 66

66 — 38 = 28 pupils

 

3–  a ->  (18s + 24) kg ,   b ->   16 kg

Mass of chicken –>  3s kg

Mass of puppy –>  (3s + 4) kg

Mass of dog –>  (3+ 3s + 4) kg × 2 = (12+ 8) kg

3s + 3s + 4 + 12s + 8 = (18s + 12) kg                   (a)

18 × 2 + 12 = 48 kg

48 kg ÷ 3 = 16 kg                           (b)

 

4–  $51.30

Total cost of 5 apples and 5 man­goes –>  $3.25 × 5 = $16.25

Cost of 3 apples –>  $17.60 — $16.25 = $1.35

Cost of 1 apple –> $1.35 ÷ 3 = $0.45

Cost of 1 mango –> $3.25 — $0.45 = $2.80

Cost of 2 man­goes and 7 apples –>  $2.80 × 2 + $0.45 × 7 = $8.70

$50 — $8.70 = $51.30

Con­tinue read­ing

  

Primary 6 March Review 7

P6-Mar-Review 7

Ans:

1–  3

2–  4

3–  4

3.30 p.m. to 4.30 p.m. –>  1st hour –> $3.50

4.30 p.m. to 5.45 p.m.–>  1 h 15 min ->  3 sets of half-hours
->  3 × $1 = $3

$3.50 + $3 = $6.50

 

4–  1

5–  2

6–  3

7–  2

75% — 50% = 25%

25% –>  105 ml

50% –>  105 ml × 2 = 210 ml

Con­tinue read­ing

  

Primary 6 Algebra Level 2 Ex 5

P6-Algebra-L2-Ex5

Ans:

1–  $(7y/2) /  $3.50y

Price of 1 durian –>  $(y/10)

$(y/10) × 35 = $(7y/2)/ $3.50y

 

2–  55

3–  (35 

4–  (4+ 10) years old

Brother’s age –>  3n + 9 — 2n = (n + 9) years old

Total age now –>  3n + 9 + n + 9 = 4n + 18 years old

4n + 18 – 4 – 4 = (4n + 10) years old

 

5–  $(m – 20)/3

6–  4.5z² cm²

Area of Tri­an­gle WXY –>  1/2 × 3z × 1.5= 2.25 z² cm²

2.25 z² × 2 = 4.5z² cm²

Con­tinue read­ing

  

Primary 6 Algebra Level 1 Ex 4

P6-Algebra-L1-Ex 4

Ans:

1–  1

2–  1

3–  4

12x + 19 + (4x × 6 ÷ 3) – 8
= 12x + 19 + 8x - 8 = 20x + 11

 

4–  2

5–  2

Amount left after giv­ing her daugh­ter —  $(800 — 40z)

Each son ->  $(800 — 40z) ÷ 3

Con­tinue read­ing

  

Primary 6 September Problem Sums 10

P6-PSP-Sep-Ex 10

Ans:

1–  See below

Qn 1

 

2–  9360 cm³

Height of water needed to fill the con­tainer –>  25 cm — 18.5 cm = 6.5 cm

45 cm × 32 cm × 6.5 cm = 9360 cm³

 

3–  68 but­tons

36 + 3 = 39 more buttons

8 — 5 = 3  buttons

∴ She needs 39 more but­tons because she is putting 3 more but­tons into each box.

39 ÷ 3 = 13 boxes

13 × 5 + 3 = 68 but­tons

 

4–  $580

107% –>  $465.45

100% –>  $435 (dis­counted price with­out GST)

75% –> $435

100% –>  435/75 × 100 = $580

 

5–  136 chil­dren

40% = 40/100 = 2/5

2/3 of the boys = 2/5 of the girls

Boys  :  Girls
3      : 5

2u –> 34

1u –> 17

17 × 8 = 136 chil­dren 

Con­tinue read­ing