PSLE Jean baked a total of 21 large and small cakes in the ratio of 5 : 2. She decorated each cake with some lychees in the ratio of 5 : 2. She used a total of 288 lychees to decorate all the small cakes and 4 large cakes.
- How many small cakes did Jean bake?
- What was the number of lychees used to decorate all the small cakes?
- How many more lychees did Jean need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
55 + 2 =
57Number of large cakes
=
57 x 21
= 15
Number of small cakes
= 21 - 15
= 6
|
Large cakes |
Small cakes |
Total |
Number |
4 |
6 |
|
Value |
5 u |
2 u |
|
Total value |
20 u |
12 u |
32 u |
(b)
Number of lychees used to decorate 4 large cakes and 6 small cakes
= 20 u + 12 u
= 32 u
32 u = 288
1 u = 288 ÷ 32 = 9
Number of lychees used to decorate all the small cakes
= 12 u
= 12 x 9
= 108
(c)
Number of lychees to decorate one large cake
= 5 u
= 5 x 9
= 45
Number of remaining large cakes that were decorated yet
= 15 - 4
= 11
Number of more lychees that Jean needed to decorate the remaining large cakes
= 11 x 45
= 495
Answer(s): (a) 6; (b) 108; (c) 495