Q&A - PSLE Math

[Spongy]

Can someone please help in this question? Thanks in advance!!!


1. Mr Ramy walks from his house to his office every morning. If he walks at a speed of 65m/min, he will be late for work by 5 minutes. If he increases his speed by 15m/min, he will be early for work by 4 minutes. How far is his office from his house?

[tianzhu]

Spongy:

Can someone please help in this question? Thanks in advance!!!


1. Mr Ramy walks from his house to his office every morning. If he walks at a speed of 65m/min, he will be late for work by 5 minutes. If he increases his speed by 15m/min, he will be early for work by 4 minutes. How far is his office from his house?

Hi
This question has been discussed before.

65*5 -------- 325

80*4 ------- 320

325 + 320 ------- 645

645/15 ------- 43 min

Distance ------- 43*65 + 325 -------- 3120m or 43*80 – 320 ------- 3120m

Best wishes

[Spongy]

tianzhu:

Spongy:

Can someone please help in this question? Thanks in advance!!!


1. Mr Ramy walks from his house to his office every morning. If he walks at a speed of 65m/min, he will be late for work by 5 minutes. If he increases his speed by 15m/min, he will be early for work by 4 minutes. How far is his office from his house?

Hi
This question has been discussed before.

65*5 -------- 325

80*4 ------- 320

325 + 320 ------- 645

645/15 ------- 43 min

Distance ------- 43*65 + 325 -------- 3120m or 43*80 – 320 ------- 3120m

Best wishes

Thanks a lot!!!

[tianzhu]

jonaandr:

3. There were twice as many chicken puffs as sardine puffs in a pastry shop. After selling 80 chicken puffs and 10 sardine puffs, there were 3 times as many sardine puffs as chicken puffs left in the shop. How many sardine puffs were there in the shop at first?

Hi

You may use MD or Units and Parts.

At first

Chicken puffs : Sardine puffs -------2u:1u

Change

Chicken puffs : Sardine puffs ------ -80 :-10

In the end

Chicken puffs : Sardine puffs -------1p:3p

2u – 80 ------ 1p

(x3)
6u – 240 ------ 3p

1u – 10 ------ 3p

5u ------ 230

1u ------ 46

Number of sardine puffs@first ------- 46

Best wishes

[tianzhu]

jonaandr:

2. Janelle went to a florist to buy some flowers. She spent 1/6 of her money on a bouquet of roses and $154 on a bouquet of lilies. She spent 1/9 of her remaining amount on a bouquet of carnation flowers. If the amount of money left was $240 more than 1/4 of the amount she had at first, how much money had she left?

Hi

You may use MD or work with units.It helps to have a simple diagram to show the apportion of units or dollar value for the different types of flowers.

Use 96 units as it’s is neat to work.

16 units ------ roses

$154 ------- lilies

8 parts (remainder) ------- 24 units + 240

1 part (carnation) -------- 3 units + 30 9 parts ------- 27 units + 270

16 + 27 ------- 43

96 – 43 ------ 53

Hence, 53 units ------- 270 +154 ------424

1 unit ------- 8

Amount of money left ------- 24 units + 240 -------432

Best wishes

[tianzhu]

jonaandr:

1. The ratio of the number of boys to the number of girls was 4:1 for Primary 6A and the ratio of the number of boys to the number of girls was 2:3 for Primary 6B.Both classes had the same number of pupils. After 4 girls left Primary 6A to join Primary 6B, the ratio of the number of boys to the number of girls in Primary 6B became 4:7. How many boys were there in Primary 6A?

Hi

Consider 6B first.

At first

Boys:Girls -------- 2u:3u

Change

Boys:Girls -------- 0 :+4

In the end

Boys:Girls -------- 4p:7p

2u ----- 4p

(x7)
14u ------ 28p

3u + 4 ------ 7p

(x4)
12u + 16 ------- 28p

14u ------- 12u + 16

1u ------- 8

Number of girls in 6B ------ 5*8 ------ 40.

Number of boys in 6A ------ 4/5*40 ------- 32

Best wishes

[Winx5015]

Hi, can anyone help me with the following questions?


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:thankyou:

[Winx5015]

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[Winx5015]

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[tianzhu]

Winx5015:

Hi, can anyone help me with the following questions?


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:thankyou:

Hi

Angle AEC ------ 36

AngleCED -------- 54

Angle KEF --------- 54 (opposite)

Angle EKF --------- 180 –(54+54) --------72 (isosceles)

Angle FGH ---------- 180 -54 ------ 126 (parallelogram)

Angle KFG ---------- 126 (angle on a straight line)

Sum ------- 252

Best wishes