Q&A - PSLE Math
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The answers given in the worksheet are a) 7:1:8 and b) 168.
But, my answer for a) was 7:11:9. You may want to try it out.
(Ai Tong School P6 SA1 Q43 - 2007)
Packets of assorted candies were sold in 2 different sizes - standard and large. The large packet contained twice as many candies as the standard packet. In the standard packet, the ratio of the number of coconut candies to the number of strawberry candies were 4:5. In the large packet, the ratio of the number of coconut candies to the number of strawberry candies to the number of toffee candies was 1: 2: 3.
A family bought 1 standard and 1 large packet.
(a) What was the ratio of the number of coconut candies to the number of strawberry candies to the number of toffee candies?
(b) The family ate 21 candies. As a result, the ratio of the number of coconut candies to the number of strawberry candies to the number of toffee candies became 2: 3: 3. How many candies were left? -
Hi Tianzhu,
Your answer is correct. My son has tried this paper before. But I remembered our answer key did have the correct answer.
Lizawa -
lizawa:
Hi LizawaHi Tianzhu,
Your answer is correct. My son has tried this paper before. But I remembered our answer key did have the correct answer.
Lizawa
Thanks, appreciate it if you could share your solution. -
Large packet
c:s:t
= 1:2:3
Standard packet
c:s
4:5
Large packet contains 2x as many candies as standard packet.
No. of units (standard packet) = 9
no. of units (large packet) = 9 2 = 18
therefore, c:s:t = 3:6:9
(a) 1 standard + 1 large, c:s:t = 7:11:9
(b)
before eating : c:s:t = 7:11:9
after eating 21 candies, c:s:t = 2:3:3 = 6:9:9
No toffee candies are eaten
18u - 15u = 21
3u = 21
u =7
candies left = 247 = 168. -
Hi lizawa
Thank you for your fast response. -
Thank You for your time in helping to solve this problem.Trying to figure out without using Algebra.
http://farm3.static.flickr.com/2407/2673911274_a92537168a_o.jpg\">
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hi tianzhu.
the area refers to the white space labeled A,B and C, or the area of the circle A, B, C ?
lizawa -
lizawa:
Hi lizawahi tianzhu.
the area refers to the white space labeled A,B and C, or the area of the circle A, B, C ?
lizawa
I believe it refers to the areas of circle A,B and C. -
Hi tianzhu,
my son said this type of question normally refers to unshaded part of A:B:C
Do you have the answer ?
Is it : 25:18:1 ? -
Solution
Total area of cirlces
(B+C) : A
= 4:5
= 24:30
1/6 of A shaded -> 1/6 * 30 = 5 units shaded
unshaded A -> 30 units - 5 units = 25 units
unshaded (B+C) -> 24 - 5 = 19 units
Can draw model here, to see clearer.
B has 5 units, C has 3 units. Size of units in B and C are different.
5 units of B + 3 units of C -> 24
1 unit of B + 1unit of C -> 5
3 units of B + 3 units of C ->15
2 units of B -> 24 - 15 = 9
unshaded B = 4 units of B -> 9 * 2 = 18
2 units of C -> 24 - 18 - 5 = 1
unshaded C = 2 units = 1
unshaded
A:B:C
= 25:18:1