PSLE Linda baked a total of 20 large and small cakes in the ratio of 7 : 3. She decorated each cake with some raspberries in the ratio of 3 : 2. She used a total of 210 raspberries to decorate all the small cakes and 10 large cakes.
- How many small cakes did Linda bake?
- What was the number of raspberries used to decorate all the small cakes?
- How many more raspberries did Linda need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
77 + 3 =
710Number of large cakes
=
710 x 20
= 14
Number of small cakes
= 20 - 14
= 6
|
Large cakes |
Small cakes |
Total |
Number |
10 |
6 |
|
Value |
3 u |
2 u |
|
Total value |
30 u |
12 u |
42 u |
(b)
Number of raspberries used to decorate 10 large cakes and 6 small cakes
= 30 u + 12 u
= 42 u
42 u = 210
1 u = 210 ÷ 42 = 5
Number of raspberries used to decorate all the small cakes
= 12 u
= 12 x 5
= 60
(c)
Number of raspberries to decorate one large cake
= 3 u
= 3 x 5
= 15
Number of remaining large cakes that were decorated yet
= 14 - 10
= 4
Number of more raspberries that Linda needed to decorate the remaining large cakes
= 4 x 15
= 60
Answer(s): (a) 6; (b) 60; (c) 60