PSLE Yen baked a total of 48 large and small cakes in the ratio of 5 : 3. She decorated each cake with some grapes in the ratio of 7 : 2. She used a total of 128 grapes to decorate all the small cakes and 4 large cakes.
- How many small cakes did Yen bake?
- What was the number of grapes used to decorate all the small cakes?
- How many more grapes did Yen need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
55 + 3 =
58Number of large cakes
=
58 x 48
= 30
Number of small cakes
= 48 - 30
= 18
|
Large cakes |
Small cakes |
Total |
Number |
4 |
18 |
|
Value |
7 u |
2 u |
|
Total value |
28 u |
36 u |
64 u |
(b)
Number of grapes used to decorate 4 large cakes and 18 small cakes
= 28 u + 36 u
= 64 u
64 u = 128
1 u = 128 ÷ 64 = 2
Number of grapes used to decorate all the small cakes
= 36 u
= 36 x 2
= 72
(c)
Number of grapes to decorate one large cake
= 7 u
= 7 x 2
= 14
Number of remaining large cakes that were decorated yet
= 30 - 4
= 26
Number of more grapes that Yen needed to decorate the remaining large cakes
= 26 x 14
= 364
Answer(s): (a) 18; (b) 72; (c) 364