PSLE Ivory baked a total of 45 large and small cakes in the ratio of 7 : 2. She decorated each cake with some raspberries in the ratio of 7 : 3. She used a total of 316 raspberries to decorate all the small cakes and 7 large cakes.
- How many small cakes did Ivory bake?
- What was the number of raspberries used to decorate all the small cakes?
- How many more raspberries did Ivory need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
77 + 2 =
79Number of large cakes
=
79 x 45
= 35
Number of small cakes
= 45 - 35
= 10
|
Large cakes |
Small cakes |
Total |
Number |
7 |
10 |
|
Value |
7 u |
3 u |
|
Total value |
49 u |
30 u |
79 u |
(b)
Number of raspberries used to decorate 7 large cakes and 10 small cakes
= 49 u + 30 u
= 79 u
79 u = 316
1 u = 316 ÷ 79 = 4
Number of raspberries used to decorate all the small cakes
= 30 u
= 30 x 4
= 120
(c)
Number of raspberries to decorate one large cake
= 7 u
= 7 x 4
= 28
Number of remaining large cakes that were decorated yet
= 35 - 7
= 28
Number of more raspberries that Ivory needed to decorate the remaining large cakes
= 28 x 28
= 784
Answer(s): (a) 10; (b) 120; (c) 784