Q&A - P5 Math

[MathIzzzFun]

smartmummy:

MathIzzzFun:

[quote=\"smartmummy\"]Pls help the following qns - no urgent.Thanks



Q2)The ratio of the number of girls to the number of boys taking part in a swimming assessment was 6:5.The assessment showed that the ratio of the number of girls' swimmers to the number of girls' non-swimmers was 5:2.The ratio of the number of boys' swimmers to the number of boys' non-swimmers was 3:2.
a)What fraction of the children were non-swimmers?
b)If there were 30 more boys' non-swimmers than girls' non-swimmers how many swimmers were there altogether?

TIA.

Total girls : boys = 6 : 5 --> 42u : 35u --- total --> 77u
Boys' swimmers : Boys' non-swimmers = 3 : 2 --> 21u : 14u

Girls' swimmers : Girls's non-swimmers = 5 : 2 --> 30u : 12u

Total number of non-swimmers = 14u + 12u = 26u
a) fraction of the children who are non-swimmers = 26/77

Total number of swimmers --> 21u + 30u = 51u
Boys' non-swimmer --> 14u
Girls' non-swimmer --> 12u
2u --> 30, 1u --> 15

Total number of swimmers --> 51 x 15 = 765

cheers.

How to find 42u : 35u --- total --> 77u,guess and check for G=G.swimmers + G.non swimmers, B=B.swimmers +B.non swimmers, or any short-cut? :thankyou:[/quote]G.swimmers + G.non-swimmers = 7, so total number of girls is a multiple of 7

since total number of girls : total number of boys = 6:5
we multiply by 7 to get --> 42 : 35

cheers.

[smartmummy]

OIC,got it.Thanks MathIzzzFun for your explanation,solution and time.

[chloecube]

MathIzzzFun:

chloecube:

Siti knitted 1 2/5m of a scarf,on Monday,she knitted 1/4 of the length.on Tuesday, she knitted 45cm more. What fraction of the scarf was knitted altogether?


answer is 4/7.

anyone can help? Thks

1 2/5 m = 1.4m = 140 cm
1/4 of 140 cm = 35 cm
Total knitted = 35 cm + 45 cm = 80 cm

Fraction of scarf knitted --> 80/140 = 4/7

cheers.

thank you
i mis-read the sentence as she did 45cm more on tue than monday

[doraemo]

pls help




(1)\tW and R collect stamps. If R gives W 15 stamps, he will have the same number of stamps as W. If W gives R 15 stamps, he will have ½ as many stamps as R. How many stamps does each of them have?


(2)\tIn April A,B C and D had a total of $324. In May , the savings of the 4 girls became equal when A’s savings was doubled, B’s savings was reduced by $4, C’s saving remained unchanged and D’s savings was increased by $9. What was B’s and D’s savings in April?

[2Transformer]

I need your help to solve this question.



Question:

The ratio of the number of library books in School ABC to the number of library books in School XYZ was 5:4. When 1424 books from School ABC were loaned to School XYZ, the ratio of the number of books in School ABC to the number of books in School XYZ became 13:14.

(a) What fraction of the books in School ABC was loaned to School XYZ ?
(b) How many books were there in School XYZ at first?

[smartmummy]

2Transformer:

I need your help to solve this question.



Question:

The ratio of the number of library books in School ABC to the number of library books in School XYZ was 5:4. When 1424 books from School ABC were loaned to School XYZ, the ratio of the number of books in School ABC to the number of books in School XYZ became 13:14.

(a) What fraction of the books in School ABC was loaned to School XYZ ?
(b) How many books were there in School XYZ at first?

ABC:XYZ
Before
5:4
15:12
After
13:14
a) 2/15 (15-13=2)
b)1424/2=712
12*712=8544

[2Transformer]

smartmummy:

2Transformer:

I need your help to solve this question.



Question:

The ratio of the number of library books in School ABC to the number of library books in School XYZ was 5:4. When 1424 books from School ABC were loaned to School XYZ, the ratio of the number of books in School ABC to the number of books in School XYZ became 13:14.

(a) What fraction of the books in School ABC was loaned to School XYZ ?
(b) How many books were there in School XYZ at first?

ABC:XYZ
5:4
15:12
After
13:14
a) 2/15 (15-13=2)
b)1424/2=712
12*712=8544

Thank you.

Btw, can you explain why the ratio 5:4 multiply by 3? And why the denominator is 15? My son does not understand it.

TIA

[smartmummy]

doraemo:

pls help

(2)\tIn April A,B C and D had a total of $324. In May , the savings of the 4 girls became equal when A’s savings was doubled, B’s savings was reduced by $4, C’s saving remained unchanged and D’s savings was increased by $9. What was B’s and D’s savings in April?

In May
A [ u ][u ]
B [ u ][u ] 4
C [ u ][u ]
D [u][u-9]

In Apr
u+2u+4+2u+2u-9=324
7u=329
u=47
B's in April=2*47+4=$98
D's in April=2*47-9=$87

[carol73]

hi

pls help
The ratio of the number of stickers Patricia has to the number James has is 5:2
when Patricia gives 50 stickerss to James, she still have 80 stickers more than James. How many stickers does James have at first

[smartmummy]

2Transformer:

smartmummy:

[quote=\"2Transformer\"]I need your help to solve this question.



Question:

The ratio of the number of library books in School ABC to the number of library books in School XYZ was 5:4. When 1424 books from School ABC were loaned to School XYZ, the ratio of the number of books in School ABC to the number of books in School XYZ became 13:14.

(a) What fraction of the books in School ABC was loaned to School XYZ ?
(b) How many books were there in School XYZ at first?

ABC:XYZ
5:4
15:12
After
13:14
a) 2/15 (15-13=2)
b)1424/2=712
12*712=8544

Thank you.

Btw, can you explain why the ratio 5:4 multiply by 3? And why the denominator is 15? My son does not understand it.

TIA[/quote]5:4 means ABC---- 5units, XYZ----4units
if we divide the one unit into three we can get ABC----5*3=15parts, XYZ--- 4*3=12parts [I divide or simply multiply by 3 to get a bigger number than 13 as 1424 books from School ABC were loaned to School XYZ]
And why the denominator is 15?
cos now total of 15parts in ABC