PSLE Esther baked a total of 28 large and small cakes in the ratio of 5 : 2. She decorated each cake with some cherries in the ratio of 8 : 5. She used a total of 240 cherries to decorate all the small cakes and 5 large cakes.
- How many small cakes did Esther bake?
- What was the number of cherries used to decorate all the small cakes?
- How many more cherries did Esther need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
55 + 2 =
57Number of large cakes
=
57 x 28
= 20
Number of small cakes
= 28 - 20
= 8
|
Large cakes |
Small cakes |
Total |
Number |
5 |
8 |
|
Value |
8 u |
5 u |
|
Total value |
40 u |
40 u |
80 u |
(b)
Number of cherries used to decorate 5 large cakes and 8 small cakes
= 40 u + 40 u
= 80 u
80 u = 240
1 u = 240 ÷ 80 = 3
Number of cherries used to decorate all the small cakes
= 40 u
= 40 x 3
= 120
(c)
Number of cherries to decorate one large cake
= 8 u
= 8 x 3
= 24
Number of remaining large cakes that were decorated yet
= 20 - 5
= 15
Number of more cherries that Esther needed to decorate the remaining large cakes
= 15 x 24
= 360
Answer(s): (a) 8; (b) 120; (c) 360