Q&A - PSLE Math

[pixiedust]

Appreciate some help with this :

http://i1197.photobucket.com/albums/aa424/pixie_dust8/mq7.jpg\">

[tianzhu]

pixiedust:

Appreciate some help with this :

http://i1197.photobucket.com/albums/aa424/pixie_dust8/mq7.jpg\">

Hi

This question has beed discussed before.

Hope this helps.

Best wishes

http://farm5.staticflickr.com/4087/5038193821_f4be6c6c88_z.jpg\">

[Spongy]

Hi please help with this question, thank you !


1. At a furniture shop, Mr Chong spent all his money on 14 study desks and 12 chairs. If he had bought 16 study desks and 7 chairs, he would have saved $231. Each chair costs $105 less than each study desk. How much money did he spend at the furniture shop?

[tianzhu]

Spongy:

Hi please help with this question, thank you !


1. At a furniture shop, Mr Chong spent all his money on 14 study desks and 12 chairs. If he had bought 16 study desks and 7 chairs, he would have saved $231. Each chair costs $105 less than each study desk. How much money did he spend at the furniture shop?

Hi

You may use MD , Units and Parts or letters of the alphabet to show the variables.

Each chair costs $105 less than each study desk.

1D ------ 1C + 105

Mr Chong spent all his money on 14 study desks and 12 chairs.

14D + 12C -------- 14C + (14*105) + 12C ------- 26C + 1470

If he had bought 16 study desks and 7 chairs, he would have saved $231.

16C + (16*105) + 7C + 231 -------- 23C + 1680 + 231 ------- 23C + 1911

26C + 1470 ------- 23C + 1911

3C -------- 441

1C ------ 147

(26*147) + 1470 ------- 5292 (amount spent@furniture shop)

Best wishes

[Winx5015]

Q1). Mr Tan had some apples and oranges in the ratio 4:5. After selling 170 apples and 25% of the oranges, the ratio of the apples to oranges left became 1:2. What was the number of fruits Mr Tan had in the end?


Q2). Michelle had 60% more cards than Adila. Usha had 35% fewer cards than Michelle. Michelle and Adila gave Usha some cards in the ratio of 3:1. As a result, Usha had 1 1/2 times as many cards as before. Given that Michelle had 238 more cards than Adila in the end, how many cards did Michelle give to Usha?

Thanks

[corneyAmber]

Winx5015:

Q1). Mr Tan had some apples and oranges in the ratio 4:5. After selling 170 apples and 25% of the oranges, the ratio of the apples to oranges left became 1:2. What was the number of fruits Mr Tan had in the end?

4: 5
16u:20u
16u : 4x5u
when 25% of orange sold, it means (3x5)u left and apples is half of oranges, hence 15/2 = 7.5u
7.5u : 15u --> (1:2)

8.5u -> 170
u -> 170/8.5 = 20
Total units remaining after selling 170 apples and 0.25% oranges
--> (7.5+15)u = 22.5u = 22.5 x 20 = 450

Hence number of fruits in the end is 450.

[tianzhu]

Winx5015:

Q2). Michelle had 60% more cards than Adila. Usha had 35% fewer cards than Michelle. Michelle and Adila gave Usha some cards in the ratio of 3:1. As a result, Usha had 1 1/2 times as many cards as before. Given that Michelle had 238 more cards than Adila in the end, how many cards did Michelle give to Usha?

Hi

This question has been discussed before.

You may use MD or UM.

Adila ----- 100 units
Michelle ------ 160 units
Usha ----- 104 units (35% fewer than M)

M and A gave some cards to U in the ratio 3:1

U ---- 1.5*104 ----- 156
Increase in number of units ----156 -104 -----52

M -----39 units
A -----13 units

In the end

M ------ 160 – 39 ------121 units
A ------ 100 -13 ------ 87 units

121 – 87 ----- 34
34 units ------238
1 unit ------ 7

M gave (39*7) or 273 cards to U.

Best wishes

[Michaelia0816]

Tianzhu, need help with these question!!!,

Websites,

1) http://t.co/FsZBYkim
2) http://t.co/0rjvY28U

[tianzhu]

Michaelia0816:

Tianzhu, need help with these question!!!,

Websites,

1) http://t.co/FsZBYkim
2) http://t.co/0rjvY28U

Hi

For Q1

QP = MN

Triangle MNQ = equilateral

Hence, angle MQN = 60 and angle MQP = 30

Triangle MPQ = isosceles

Angle MPQ =( 150-30)/2 = 75

Angle MPN = 75*2 = 150

For Q2

Consider triangle DEF, angle DFE = 60 (equilateral)
Angle CFD = 180 – 60 - 92 = 28

Consider triangle ABC, angle ACB = 60 (equilateral)
Angle BCF = 180 – 60 – 62 = 58

At intersection of line BC and DF, label as point J
Angle CJF = 180 -58 – 28 = 94

At intersection of line BC and line DE, label as point K
Consider triangle DJK

Angle DJK = 94 (opposite angles)

Angle DKJ = 180 – 94 – 60 = 26

Angle X = 180 – 26 = 154 (angles on a straight line)

Best wishes

[Michaelia0816]

Thx you