PSLE Cindy baked a total of 30 large and small cakes in the ratio of 7 : 3. She decorated each cake with some lychees in the ratio of 3 : 2. She used a total of 240 lychees to decorate all the small cakes and 4 large cakes.
- How many small cakes did Cindy bake?
- What was the number of lychees used to decorate all the small cakes?
- How many more lychees did Cindy need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
77 + 3 =
710Number of large cakes
=
710 x 30
= 21
Number of small cakes
= 30 - 21
= 9
|
Large cakes |
Small cakes |
Total |
Number |
4 |
9 |
|
Value |
3 u |
2 u |
|
Total value |
12 u |
18 u |
30 u |
(b)
Number of lychees used to decorate 4 large cakes and 9 small cakes
= 12 u + 18 u
= 30 u
30 u = 240
1 u = 240 ÷ 30 = 8
Number of lychees used to decorate all the small cakes
= 18 u
= 18 x 8
= 144
(c)
Number of lychees to decorate one large cake
= 3 u
= 3 x 8
= 24
Number of remaining large cakes that were decorated yet
= 21 - 4
= 17
Number of more lychees that Cindy needed to decorate the remaining large cakes
= 17 x 24
= 408
Answer(s): (a) 9; (b) 144; (c) 408