Ans:

1– **3**

2– **4**

3– **2**

4– **4**

Length of rectangle –> (*z*+ 7) cm

*z* + *z* + 7 + *z* +* z*+ 7 =** (4 z + 14) cm**

5– **1**

6– **2**

4 pencils –> *n cents*

20 pencils -> *n*¢× 5 = 5*n *¢

5*n* cents – $1 = **(5 n – 100) cents**

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Ans:

1– **3**

2– **4**

3– **2**

4– **4**

Length of rectangle –> (*z*+ 7) cm

*z* + *z* + 7 + *z* +* z*+ 7 =** (4 z + 14) cm**

5– **1**

6– **2**

4 pencils –> *n cents*

20 pencils -> *n*¢× 5 = 5*n *¢

5*n* cents – $1 = **(5 n – 100) cents**

Tagged easy, Maths, mcq, Primary 6, problem solving, Singapore, Singapore Maths, Worksheets

Ans:

11u –> 2068

1u –> 188

188 × 2 = **376 women**

2– **$49**

Cost of 25 crates of apples –> $58 × 25 = $1450

Cost of 3 crates of oranges — $1597 – $1450 = $147

$147 ÷ 3 = **$49**

3– **$17**

Cost of 6.5 kg of prawns –> $24 × 6.5 kg = $156

Cost of 2 kg of fish –> $190 – $156 = $34

$34 ÷ 2 =** $17 **

Tagged CA2, Maths, Primary 4, problem solving, problem sums, revision, Singapore, Singapore Maths, word problems, Worksheets

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**

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**

Tagged difficult, easy, Maths, mcq, Prelims, Primary 6, problem solving, problem sums, PSLE, revision, Singapore, Singapore Maths, Worksheets

Ans:

1– **8 markers**

2– **8 stamps**

3– **569 stickers**

4– **776 stamps**

5– **40 pupils**

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**

Posted in Primary 2, Whole Numbers

Tagged difficult, Level 3, Maths, Primary 2, problem solving, problem sums, Singapore, Singapore Maths, Whole Numbers, word problems

Ans:

1– **175**

2– **$43.50**

70% of the price –> $101.50

30% –> $101.50/70 × 30 = **$43.50**

3– **(3 m + 6) kg**

Alan’s mass -> (*m *+ 3) kg

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

Brett’s mass -> (*m *+ 1) + 1 = (*m *+ 2) kg

(*m + *3) + (*m *+ 1) + (*m *+ 2) = **(3***m ***+ 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**

Tagged difficult, heuristic, Maths, Paper 2, Primary 6, problem solving, problem sums, PSLE, revision, SA1, Singapore, Singapore Maths, word problems, Worksheets

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**

Posted in Primary 2, Whole Numbers

Tagged difficult, Level 3, Maths, Paper 2, problem solving, problem sums, Singapore, Singapore Maths, Whole Numbers, word problems, Worksheets

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 -> **(18 s + 24) kg **, b ->

Mass of chicken –> 3*s* kg

Mass of puppy –> (3*s* + 4) kg

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

3*s + *3*s + *4 + 12*s* + 8 = **(18 s + 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**

Posted in Primary 6, Problem Sums

Tagged difficult, heuristic, Maths, Primary 6, problem solving, problem sums, revision, Singapore, Singapore Maths, Worksheets

Ans:

1– **$96**

2– **28 sweets**

If 1 add 12 more sweets to Jacqueline, she will have 1 unit.

4u –> 100 + 12 = 112

112 ÷ 4 = **28 sweets**

3– a -> **$8250 **b -> **$2475**

Amount of money Melanie spent in January –> $825 × 2 = $1650

$1650 × 5 = **$8250 **(a)

$825 + $1650 = **$2475 **(b)

4– **5/8 m**

5– **1175 stamps**

Roger –> 1u

Joshua –> 4u

4u – 1u = 3u

3u –> 705 stamps

1u –> 235 stamps

235 × 5u = **1175 stamps**

Posted in Primary 4, Problem Sums

Tagged difficult, heuristic, Maths, Primary 4, problem solving, problem sums, revision, Singapore, Singapore Maths, Worksheets

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**

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**

2u –> $1505 – $201.40 = $1303.60

$1303.60 ÷ 2 =** $651.80**

6– **$15.50**

2u– $108 – $71 = $37

1u — $18.50

Megan –> $18.50 × 3 = $55.50

$71 – $55.50 = **$15.50**

Posted in Primary 5, Problem Sums

Tagged difficult, heuristic, Maths, Paper 2, problem solving, revision, Singapore Maths, word problems, Worksheets