Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.



Question

primary 5 | Maths | Fractions
2 Answers Below

Anyone can contribute an answer, even non-tutors.

Answer This Question
Vk
Vk

primary 5 chevron_right Maths chevron_right Fractions chevron_right Singapore

I don't know what is the next step . I just managed to get 39 but I think not end yet.

Date Posted: 3 years ago
Views: 284
J
J
3 years ago
Sugar : $2.50 per pack
Cocoa powder : $6.50 per pack


Concept : grouping


Since there are thrice as many packets of sugar bought as packets of cocoa powder, their ratio is 3 : 1


Group every 3 packets of sugar with 1 packet of cocoa powder.

Total cost in 1 group

= $2.50 × 3 + $6.50
= $7.50 + $6.50
= $14


Number of groups you can get with $546

= $546 ÷ $14
= 39


Since there are 3 packets of sugar in every group,


Number of sugar packets bought

= 39 × 3
= 117
Vk
Vk
3 years ago
Yes I got it right but just not sure why 39 x 3 . So weirdo. Means 39 pack x 3 sugar . Find it no logic
J
J
3 years ago
It's not 39 packs × 3 sugar.
It's 39 Groups × 3 packets of sugar in each group.
J
J
3 years ago
You have to × 3 because when you grouped the cocoa and sugar packets together,

Every group has 1 cocoa pack and 3 sugar packets.


2 groups would be :
2 cocoa packs and 6 sugar packs


3 groups would be :
3 cocoa packs and 9 sugar packs.


39 groups would be :
39 cocoa packs and 117 sugar packs.


The idea of grouping is that the ratio always stays the same.


39 : 117 = 3 : 9 = 2 : 6 = 1 : 3

The simplest ratio is always 1 : 3. Which satisfies the question information that there are 3 times as many sugar packets bought as compared to cocoa packets
Vk
Vk
3 years ago
Ooo so 39 is coco and sugar must x3 . I got it . Thanks

See 2 Answers

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
sstrike
Sstrike's answer
5369 answers (A Helpful Person)
$2.50 : $4 = 5 : 8
5×3+1×(5+8) = 28
$546÷28 = $19.50
5×3×19.50÷2.50 = 117 (Ans)
Vk
Vk
3 years ago
How to get 5:8 ?
sstrike
Sstrike
3 years ago
2.5:4=5:8
(×2 at both sides)
sstrike
Sstrike
3 years ago
It's been stated in the picture already
Vk
Vk
3 years ago
Oh. 2.50 also can be ratio
Vk
Vk
3 years ago
Thank thank . I got it. Thank you
J
J
3 years ago
Usually for ratio we leave it in whole numbers at your level.


So the 2.50 : 4 is changed to 5 : 8
sstrike
Sstrike
3 years ago
Vk u r welcome
You have one more step to go. See main comments for explanation.
done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
J
J's answer
1022 answers (A Helpful Person)