Tag Archives: word problems

Primary 6 Prelims Revision 9

P6-Prelims-Ex 9

Ans:

1– $45

Julian –> 1u

Fred­er­ick –> 2u

Mar­cus –> 6u

5u –> $25

1u –> $5

$5 × 9u = $45

 

2–  16 more tricycles

Assume all are tri­cy­cles –> 56 × 3 = 168 wheels

168 — 148 = 20 wheels extra

Each bicy­cle has 1 lesser wheel than each tricycle.

There­fore, 20 ÷ 1 = 20 bicycles

56 — 20 00= 36 tricycles

36 — 20 = 16 more tri­cy­cles than bicycles

 

3–  $44

4–  22.5 km/h faster

Mar­cus’ speed –>  270 /4 = 67.5 km/h

Mar­cus’ new speed –>  270/3 = 90 km/h

90 km/h — 67.5 km/h = 22.5 km/h faster

 

5–  396 boys

Girls –>  1u × 5 = 5u

Boys –>  (1u + 16) × 3 = 3u + 48

8u + 48 –>  976 pupils

8u –> 928

1u –> 116

116 × 3 + 48 = 396 boys

 

6–  $2945

7 hand­bags + 5 watches = 3 hand­bags + 11 watches

7 hand­bags — 3 hand­bags = 11 watches — 5 watches

4 hand­bags = 6 watches

6 watches –>  $285 × 4 = $1140

1 watch –>  $1140 ÷ 6 = $190

$285 × 7 + $190 × 5 = $2945

 

7–  300 stick­ers

Maxwell –> 100%

Jeanet­ter –> 120%

20/100 × 120% = 24%

120%  - 24% = 96% left

96% –>  288 stickers

1% — 3 stickers

3 × 100 = 300 stick­ers

 

8–  153 cm

17 + 13 = 30 cm — 3 pieces

1 piece –>  10 cm

14 × 10 cm + 13 cm = 153 cm

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 2 Whole Numbers Level 3 Ex 2

P2-Whole Numbers-L3-Ex 2

Ans:

1–  8 mark­ers

 

2–  8 stamps

3–  569 stick­ers

4–  776 stamps

5–  40 pupils

Qn 5

Num­ber of girls –> 30 ÷ 3 = 10

30 + 10 = 40 pupils

 

6–  9 beads

Total num­ber of beads they had –>  76 + 45 = 121

130 — 121 = 9 beads

 

7–  720 stick­ers

Num­ber of stick­ers Tanya has –>  341 + 38 = 379

379 + 341 = 720 stick­ers

 

8–  537 stamps

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 2 Whole Numbers Level 3 Ex 1

P2-Whole Numbers-L3-Ex 1

Ans:

1–  241 mar­bles

2–  538 stamps

Num­ber of stamps Irene has –>  325 — 112 = 213

325 + 213 = 538 stamps

 

3–  202 mar­bles

4–  40 pupils

5–  30 apples

Num­ber of apples in each bas­ket –>  2 + 3 = 5

5 × 6 = 30 apples

Con­tinue read­ing

Primary 3 Whole Numbers Level 3 Ex 4

P3-Whole Numbers-L3-Ex 4

Ans:

1–  4200 beads

Qn 1

Num­ber of beads Jen­nifer has –>  1866 + 468 = 2334

2334 + 1866 = 4200 beads

 

2–  195 steps

3–  67 cook­ies

4–  a –>  1277 men   ,   b ->  1085 more men

Num­ber of men who par­tic­i­pated –>  1277 — 89 = 1188

Num­ber of women who par­tic­i­pated –>  123 — 20 = 103

1188 — 103 =1085 more men 

 

5–  5460 stick­ers 

Num­ber of months from Feb­ru­ary to Octo­ber –> 9

9 × 20 = 180 more than January

5280 + 180 = 5460 stick­ers

 

6–  $712

Total amount of money Melody and Lisa have –>  $2835 + $4259 = $7094

Amount of money each of them has in the end –>  $7094 ÷ 2 = $3547

$4259 — $3547 = $712

Con­tinue read­ing

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 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

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

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

Con­tinue read­ing