PSLE Penelope baked a total of 24 large and small cakes in the ratio of 5 : 3. She decorated each cake with some cranberries in the ratio of 5 : 2. She used a total of 132 cranberries to decorate all the small cakes and 3 large cakes.
- How many small cakes did Penelope bake?
- What was the number of cranberries used to decorate all the small cakes?
- How many more cranberries did Penelope need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
55 + 3 =
58Number of large cakes
=
58 x 24
= 15
Number of small cakes
= 24 - 15
= 9
|
Large cakes |
Small cakes |
Total |
Number |
3 |
9 |
|
Value |
5 u |
2 u |
|
Total value |
15 u |
18 u |
33 u |
(b)
Number of cranberries used to decorate 3 large cakes and 9 small cakes
= 15 u + 18 u
= 33 u
33 u = 132
1 u = 132 ÷ 33 = 4
Number of cranberries used to decorate all the small cakes
= 18 u
= 18 x 4
= 72
(c)
Number of cranberries to decorate one large cake
= 5 u
= 5 x 4
= 20
Number of remaining large cakes that were decorated yet
= 15 - 3
= 12
Number of more cranberries that Penelope needed to decorate the remaining large cakes
= 12 x 20
= 240
Answer(s): (a) 9; (b) 72; (c) 240