Q&A - PSLE Math

[jieheng]

YumYum:

Hi, Can anyone pls help with this Qn:


Calvin had $840 more than Daniel. Calvin gave 75% of his money to Daniel. Daniel gave 5/7 of his money to Calvin. In the end, Calvin had $700 more than Daniel. How much did Calvin have at first?

Thanks!

At first
C 4u + 840
D 4u

Calvin gave 75% of his money to Daniel
C gave 3u + 630 to D

C 1u + 210
D 7u + 630

Daniel gave 5/7 of his money to Calvin
D gave 5u + 450 to C

C 6u + 660
D 2u + 180

(6u + 660) - (2u + 180) --> 700
4u + 480 --> 700
4u --> 220

4u + 840 --> 220 + 840 = 1060 (Ans)

[jieheng]

Jolyn:

Mandy ate 5/12 of her cookies and gave 3/7 of the remainder to jane. If she had 16 cookies left, how many cookies did Mandy have at first?



Hope you can reply me by today.

No of cookies , 12u

Mandy at 5/12 of her cookies , 5u ; she left 7u

She gave 3/7 of the remainder to Jane ; she gave 3u to Jane

Mandy left 4u

4u --> 16
1u --> 4

12u --> 12x4 = 48 (Ans)

[YumYum]

jieheng:

YumYum:

Hi, Can anyone pls help with this Qn:


Calvin had $840 more than Daniel. Calvin gave 75% of his money to Daniel. Daniel gave 5/7 of his money to Calvin. In the end, Calvin had $700 more than Daniel. How much did Calvin have at first?

Thanks!

At first
C 4u + 840
D 4u

Calvin gave 75% of his money to Daniel
C gave 3u + 630 to D

C 1u + 210
D 7u + 630

Daniel gave 5/7 of his money to Calvin
D gave 5u + 450 to C

C 6u + 660
D 2u + 180

(6u + 660) - (2u + 180) --> 700
4u + 480 --> 700
4u --> 220

4u + 840 --> 220 + 840 = 1060 (Ans)

Jieheng, thank you for yr help

[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?

[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?