Q&A - P5 Math

[happyheart]

Can someone help to explain the concept of <No x value and inverse proportion>? Below are 2 similar type questions based on the concept. Thanks in advance.



Q1) A group of children was given 136 candies on Children’s Day. Each girl received 3 candies and each boy received 4 candies. There were 6 more boys than girls in the group. How many girls were there in the group?


Q2) A group of children was given some candies on Children’s Day. Each girl received 3 candies and each boy received 5 candies. There were 3/4 as many boys as girls in the group. If the boys received 60 sweets more than the girls, how many girls were there in the group?

[tianzhu]

happyheart:

Q1) A group of children was given 136 candies on Children's Day. Each girl received 3 candies and each boy received 4 candies. There were 6 more boys than girls in the group. How many girls were there in the group?

Hi

Good Morning.

You may use the “Grouping concept”

Each girl ------ 3 candies

Each boy ------ 4 candies

There were 6 more boys than girls in the group.

6*4 ------ 24

136 - 24 ------- 112

Consider a group of 1 boy and 1 girl.

1 boy + 1 girl ------- 7 candies

112/7 ------ 16

There were 16 groups.

Number of girls ------ 16

Number of boys ------- 16 + 6 ------ 22

Best wishes

[tianzhu]

happyheart:

Q2) A group of children was given some candies on Children's Day. Each girl received 3 candies and each boy received 5 candies. There were 3/4 as many boys as girls in the group. If the boys received 60 sweets more than the girls, how many girls were there in the group?

Hi

Boy ------- 3 units

Girls ------ 4 units

Using the concept of “Number*Value”, you may tabulate it if you prefer.

Boy ------- 3*5 -------- 15 units

Girl ------- 4*3 -------- 12 units

15 – 12 ------- 3

3 units -------- 60

1 unit ------- 20

Number of girls -------- 4*20 -------- 80

Check

Number of sweets received by boys -------- 60*5 ------- 300

Number of sweets received by girls -------- 80*3 ------- 240

Difference ------- 300 – 240 ------- 60

Best wishes

[happyheart]

tianzhu:

happyheart:

Q2) A group of children was given some candies on Children's Day. Each girl received 3 candies and each boy received 5 candies. There were 3/4 as many boys as girls in the group. If the boys received 60 sweets more than the girls, how many girls were there in the group?

Hi

Boy ------- 3 units

Girls ------ 4 units

Using the concept of “Number*Value”, you may tabulate it if you prefer.

Boy ------- 3*5 -------- 15 units

Girl ------- 4*3 -------- 12 units

15 – 12 ------- 3

3 units -------- 60

1 unit ------- 20

Number of girls -------- 4*20 -------- 80

Check

Number of sweets received by boys -------- 60*5 ------- 300

Number of sweets received by girls -------- 80*3 ------- 240

Difference ------- 300 – 240 ------- 60

Best wishes

Thank you, Tianzhu.

[Udon]

Hi hi...seek help for better solution...


Q1. Maria spent $480 on food and 25% of her money on clothes and had $1020 left. What percentage of her money did she spend?


$480+$1020=100%-25%
$1500=75%
1%=1500/75
1%=20

25%=25x20=$500

$1500+$500=$2000

480/2000*100=24%

24%+25%=49%

Total % spent 49%

was this solution too long winded? Please assist.
Thank you.

[happyheart]

please help. Thank you in advance!


Q) Ali used some rectangular and square tiles to make a wall design. The rectangular tiles were sold at 3 for $12 and the square tiles were sold at 2 for $6. If he spend $546 on an equal number of rectangulars and square tiles, how many rectangular Nd square tiles dis he use altogether?

[cimman]

Udon:

Hi hi...seek help for better solution...


Q1. Maria spent $480 on food and 25% of her money on clothes and had $1020 left. What percentage of her money did she spend?


$480+$1020=100%-25%
$1500=75%
1%=1500/75
1%=20

25%=25x20=$500

$1500+$500=$2000

480/2000*100=24%

24%+25%=49%

Total % spent 49%

was this solution too long winded? Please assist.
Thank you.

here is an alternative method:
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[pineapple tarts]

Sorry to trouble u guys again. Pls help me with this question. Thank you.


In May, the ave. nos. of participants in one pottery class was 24. In June, 5 new pottery class were added. The ave. nos. of the participants in all pottery class became 26. If there were 32 participants in each of the new pottery classes, find the total nos. of participants in all pottery classes in June.

[pineapple tarts]

One more…


Don and Larry had 315 stickers altogether. Don gave ¼ of his stickers to Larry. After that, Larry gave ½ of all he had to Don. In the end, Don had twice as many sticker as Larry.
(a) how many stickers did Don have at first?
(b) how many stickers did Larry have at first?

[pineapple tarts]

Sorry sorry, last one for the day.


At 2p.m. the ratio of the nos. of girls to the nos. of boys at the library was 5:3. After 2p.m., 40 girls left the library and 40 boys entered the library and the ratio became 3:4.
(a) how many girls were there at the library at first?
(b) how many more boys were there at the library after 2p.m.?