Q&A - PSLE Math

[jieheng]

bndreve:

Hi, pls help with this Qns. Thanks.


Soo Kee had $1390 more than Poh Heng. Soo Kee paid for a ring with 3/5 of her money and Poh Heng paid for a pair of ear rings with 75% of her money. Then Soo Kee had $964 more than Poh Heng. What is the sum of money did both of them have at first?

At first
SK 20u + 1390
PH 20u

Soo Kee paid for a ring with 3/5 of her money
SK paid 12u + 834

Poh Heng paid for a pair of ear rings with 75% of her money
PH paid 15u

SK (20u + 1390) - (12u + 834) = 8u + 556
PH (20u) - (15u) = 5u

Then Soo Kee had $964 more than Poh Heng

(8u + 556) - 5u --> 964
3u --> 408
1u --> 136

40u + 1390 --> 40x136 + 1390 = 6830 (Ans)

[bndreve]

jieheng, thanks for your help.

[Jolyn]

45% of a vegetable garden is planted with peas. 3/5 of the remaining area is planted with beans and the rest is planted with potatoes. The area of the garden is 121m2. Find the area planted with potatoes?


Hope you can reply it by today

[jieheng]

Jolyn:

45% of a vegetable garden is planted with peas. 3/5 of the remaining area is planted with beans and the rest is planted with potatoes. The area of the garden is 121m2. Find the area planted with potatoes?


Hope you can reply it by today

Peas 45%
Beans 3/5*55% = 33%
Potatoes 100% - 45% - 33% = 22%

100% --> 121
1% --> 1.21
22% --> 22*1.21 = 26.62 (Ans)

[happyheart]

Hi,

pls help with this question. Thanks!

Andy, Brad, Colin shared money to buya present for their teacher. The ratio of the amount of money contributed by Andy to the total amount contributed by Brad, Colin and Dominic was 1:5. Brad contributed 1/11as much as the total contributed by Dominic. If Andy contributed $2.10 more than Brad, how much did Dominic contribute?

[happyheart]

Hi, one more please. I am always confused when there is transfer back and forth.Thanks.


Jack and Aqil had some game cards. If Jack gave Aqil 52 cards, he would have the same number of cards as Aqil. If Aqil gave Jack 34 cards, the ratio of the number of cards Aqil had to the number of cards Jack had would be 3:7.How many cards did Jack have at first?

[MathIzzzFun]

happyheart:

Hi, one more please. I am always confused when there is transfer back and forth.Thanks.


Jack and Aqil had some game cards. If Jack gave Aqil 52 cards, he would have the same number of cards as Aqil. If Aqil gave Jack 34 cards, the ratio of the number of cards Aqil had to the number of cards Jack had would be 3:7.How many cards did Jack have at first?

If Jack gave Aqil 52 cards, he would have the same number of cards as Aqil
--> Jack has 52 x 2 = 104 more cards than Aqil at first.

If Aqil gave Jack 34 cards,
--> Jack would have 104 + 34 x 2 = 172 more cards than Aqil

So, 4u --> 172, 1u --> 43
Number of cards Jack has at first = 7 x 43 - 34 = 267

cheers.

[MathIzzzFun]

happyheart:

Hi,

pls help with this question. Thanks!

Andy, Brad, Colin shared money to buya present for their teacher. The ratio of the amount of money contributed by Andy to the total amount contributed by Brad, Colin and Dominic was 1:5. Brad contributed 1/11as much as the total contributed by Dominic. If Andy contributed $2.10 more than Brad, how much did Dominic contribute?

...seems that some info was left out ??

cheers.

[Jwoofamily]

Use model.


If jack give aqil 52 cards and they have same number means the model is like this.

J [ ][ 52 ][ 52 ]
A [ ]

If A gives 34 to J, the model will be as shown below whereby 34+34+52+52=4 units.

J [][][][34][34][ 52 ][ 52 ]
A [][][]

Find 1 unit and you can find solve the problem by tracing back to the original quantity.

[tianzhu]

happyheart:

Hi,

pls help with this question. Thanks!

Andy, Brad, Colin shared money to buya present for their teacher. The ratio of the amount of money contributed by Andy to the total amount contributed by Brad, Colin and Dominic was 1:5. Brad contributed 1/11as much as the total contributed by Dominic. If Andy contributed $2.10 more than Brad, how much did Dominic contribute?

Hi

One possible solution.

A:(: (B+C+D) ------- 1:5 -------3:15

B:D ------1:11

Hence , C ------3

2u ------ 2.1

1u ------ 1.05

D ------- 11*1.05 ------ 11.55

Best wishes