I would solve the question as follows :tanxexy wrote:Jerico wrote:

Kindly help. Thank you very much !

(a) Area of the square = 2(1/2 times 2x times x) = 2(x^2) sq cm.

(b) Area of shaded segments = (pi time x time x) – 2(x^2) = (pi – 2)x^2 sq cm.

Academic support for Primary 6 and PSLE

- alfretztay
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by **alfretztay** » Tue Jan 06, 2015 8:58 pm

I would solve the question as follows :tanxexy wrote:Jerico wrote:

Kindly help. Thank you very much !

(a) Area of the square = 2(1/2 times 2x times x) = 2(x^2) sq cm.

(b) Area of shaded segments = (pi time x time x) – 2(x^2) = (pi – 2)x^2 sq cm.

- alfretztay
- KiasuGrandMaster
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by **alfretztay** » Wed Jan 07, 2015 11:29 am

I am careless at times too. And you are most welcome; MathWithModels!MathWithModels wrote:Yes, sorry. I was careless in part b. Thanks for the correction, alfretztay!Daddy wrote:

MathWithModels.

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by **PlayfulFairy** » Thu Jan 08, 2015 11:19 pm

Please help me with these sums.. Thanks !

1) Mdm Siti made some jellies. She gave 4 less than 50% of all the jellies to her mother. She also gave 6 more than 1/4 of the rest of the jellies to her friends. She then had 15 jellies left. How many jellies did she make together at first ? (48 jellies)

2) Jane used some beads in the morning for her handicraft. In the afternoon, she used 62.5% of the remaining beads. As a result, the ratio of the number of beads left to the number of beads at first was 15:58. What was the percentage increase in beads that she used in the afternoon when compared to the morning? (38.9%)

1) Mdm Siti made some jellies. She gave 4 less than 50% of all the jellies to her mother. She also gave 6 more than 1/4 of the rest of the jellies to her friends. She then had 15 jellies left. How many jellies did she make together at first ? (48 jellies)

2) Jane used some beads in the morning for her handicraft. In the afternoon, she used 62.5% of the remaining beads. As a result, the ratio of the number of beads left to the number of beads at first was 15:58. What was the percentage increase in beads that she used in the afternoon when compared to the morning? (38.9%)

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by **MathWithModels** » Fri Jan 09, 2015 10:20 am

Hi PlayfulFairy,PlayfulFairy wrote:Please help me with these sums.. Thanks !

1) Mdm Siti made some jellies. She gave 4 less than 50% of all the jellies to her mother. She also gave 6 more than 1/4 of the rest of the jellies to her friends. She then had 15 jellies left. How many jellies did she make together at first ? (48 jellies)

We are given some numbers, 50% and 1/4. So let's divide the jellies into quarters. So we have 4u jellies to start with.

She gave 4 less than half to her mother.

This means Siti's mother has 2u - 4 jellies.

So, Siti has 4u - (2u - 4) = 2u + 4 jellies left.

1 / 4 of the remainder is (2u + 4) / 4 = u/2 + 1

Siti gave 6 more than this to her friends.

So her friends have u/2 + 1 + 6 = u/2 + 7 jellies.

Siti has 15 jellies left.

All the jellies = Jellies to mother + Jellies to friends + Jellies left

4u = (2u - 4) + (u/2 + 7) + 15

Bringing all the

4u - 2u - u/2 = 15 + 7 - 4

3u / 2 = 18

u = 12

So, all the jellies are 4u = 4 x 12 = 48 jellies.

MathWithModels

Last edited by MathWithModels on Fri Jan 09, 2015 11:46 am, edited 1 time in total.

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by **Ice watch** » Fri Jan 09, 2015 10:56 am

PlayfulFairy wrote:Please help me with these sums.. Thanks !

1) Mdm Siti made some jellies. She gave 4 less than 50% of all the jellies to her mother. She also gave 6 more than 1/4 of the rest of the jellies to her friends. She then had 15 jellies left. How many jellies did she make together at first ? (48 jellies)

2) Jane used some beads in the morning for her handicraft. In the afternoon, she used 62.5% of the remaining beads. As a result, the ratio of the number of beads left to the number of beads at first was 15:58. What was the percentage increase in beads that she used in the afternoon when compared to the morning? (38.9%)

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by **PlayfulFairy** » Fri Jan 09, 2015 5:11 pm

Thank you so much for all who responded!!

I am encountering great difficulty solving problem sums involving heuristics and DD is taking PSLE in a few months time. How can I brush up my skills? :$

I am encountering great difficulty solving problem sums involving heuristics and DD is taking PSLE in a few months time. How can I brush up my skills? :$

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