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[MathIzzzFun]

Neat:

Hi! Morning,


Please help to solve the following question:

There were 2/9 as many red beads as blue beads in a bag. When some blue beads were taken out and an equal number of red beads were added into the bag, the number of red beads became 1/4 of the total number of beads in the bag. If there were 176 beads in the bag at first, how many blue beads were taken out from the bag?

Thanks you in advance.

Hi

The total number of beads remained unchanged.

Initially, number of blue beads = 9/(2+9) x 176 = 144
In the end, number of blue beads = 3/4 x 176 = 132
Number of blue beads taken out = 144 - 132 = 12

cheers.

[Andrew Lee]

Adam Ma:

May I know what level of class this problem comes from?

It from Red Swastika,P6,2010,Prelim

[Andrew Lee]

MadScientist:

Here goes...


A) [ 5 / (5+9) ] = 35.71% of the circle is shaded.

B) 168 * 35.71% = 60 sqcm
Since AE = EB, Triangle is an isoceles triangle (ie. two equal sides)
And shaded part is 40% of triangle, therefore, 60 sqcm is 40% of triangle.
Area of triangle DEC = (100/40) x 60 = 150 sqcm

But the answer for Q15a is 20% is shaded & 15b is 75sqcm :slapshead:

[Andrew Lee]

Andrew Lee:

MadScientist:

Here goes...


A) [ 5 / (5+9) ] = 35.71% of the circle is shaded.

B) 168 * 35.71% = 60 sqcm
Since AE = EB, Triangle is an isoceles triangle (ie. two equal sides)
And shaded part is 40% of triangle, therefore, 60 sqcm is 40% of triangle.
Area of triangle DEC = (100/40) x 60 = 150 sqcm

But the answer for Q15a is 20% is shaded & 15b is 75sqcm :slapshead:

Can help me solve Q20 :?
http://i53.tinypic.com/2ld831i.jpg\">

[whywhy]

Tin A contains some 20-cents coins and Tin B contains some 50-cents coins.

There are 9 more coins in Tin A than in Tin B.
The amount of money in Tin A is $2.70 less than that in Tin B.
How many 50-cents coins are there in Tin B ?

Please help, Thank u

[Andrew Lee]

Here goes...


A) [ 5 / (5+9) ] = 35.71% of the circle is shaded.

B) 168 * 35.71% = 60 sqcm
Since AE = EB, Triangle is an isoceles triangle (ie. two equal sides)
And shaded part is 40% of triangle, therefore, 60 sqcm is 40% of triangle.
Area of triangle DEC = (100/40) x 60 = 150 sqcm[/quote]

But the answer for Q15a is 20% is shaded & 15b is 75sqcm :slapshead:[/quote]

Can help me solve this question, Q3 ? tks :?
http://i55.tinypic.com/2jg0x2c.jpg\">

[Andrew Lee]

Andrew Lee:

Andrew Lee:

[quote=\"MadScientist\"]Here goes...


A) [ 5 / (5+9) ] = 35.71% of the circle is shaded.

B) 168 * 35.71% = 60 sqcm
Since AE = EB, Triangle is an isoceles triangle (ie. two equal sides)
And shaded part is 40% of triangle, therefore, 60 sqcm is 40% of triangle.
Area of triangle DEC = (100/40) x 60 = 150 sqcm

But the answer for Q15a is 20% is shaded & 15b is 75sqcm :slapshead:

[/quote]

[tdes]

The ratio of the number of girls to the number of boys in a school is 5:8. After 538 girls and 538 boys left the school, the ratio of girls to boys in the school is now 3:7.


How many students were there in the school at the beginning?

Thanks!

[blitz]

Help please.

Tracy counted the number of 10cents coins, 20cent coins and 50cents coins in her piggy bank. The number of 10c coins was 24 more than the number of 50c coins. After spending 3/5 of the 10c coins, 1/4 of the 20c coins and 18 50c coins, she had an equal number of 10c and 20c coins. The number of 50c coins now formed 40% of the remaining number of coins.

(a) How many 10c coins did Tracy have at first?
(b) How much did she spend in all?

[MathIzzzFun]

whywhy:

Tin A contains some 20-cents coins and Tin B contains some 50-cents coins.

There are 9 more coins in Tin A than in Tin B.
The amount of money in Tin A is $2.70 less than that in Tin B.
How many 50-cents coins are there in Tin B ?

Please help, Thank u

Hi

this was discussed before - http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=27&t=149&start=1220

cheers.