PSLE Lina baked a total of 36 large and small cakes in the ratio of 7 : 5. She decorated each cake with some cranberries in the ratio of 5 : 2. She used a total of 240 cranberries to decorate all the small cakes and 10 large cakes.
- How many small cakes did Lina bake?
- What was the number of cranberries used to decorate all the small cakes?
- How many more cranberries did Lina need to decorate the remaining large cakes?
(a)
Number of large cakes
=
712 x 36
= 21
Number of small cakes
= 36 - 21
= 15
|
Large cakes |
Small cakes |
Total |
Number |
10 |
15 |
|
Value |
5 u |
2 u |
|
Total value |
50 u |
30 u |
80 u |
(b)
Number of cranberries used to decorate 10 large cakes and 15 small cakes
= 50 u + 30 u
= 80 u
80 u = 240
1 u = 240 ÷ 80 = 3
Number of cranberries used to decorate all the small cakes
= 30 u
= 30 x 3
= 90
(c)
Number of cranberries to decorate one large cake
= 5 u
= 5 x 3
= 15
Number of remaining large cakes that were decorated yet
= 21 - 10
= 11
Number of more cranberries that Lina needed to decorate the remaining large cakes
= 11 x 15
= 165
Answer(s): (a) 15; (b) 90; (c) 165