PSLE Opal baked a total of 45 large and small cakes in the ratio of 7 : 2. She decorated each cake with some cherries in the ratio of 5 : 2. She used a total of 180 cherries to decorate all the small cakes and 8 large cakes.
- How many small cakes did Opal bake?
- What was the number of cherries used to decorate all the small cakes?
- How many more cherries did Opal 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 |
8 |
10 |
|
Value |
5 u |
2 u |
|
Total value |
40 u |
20 u |
60 u |
(b)
Number of cherries used to decorate 8 large cakes and 10 small cakes
= 40 u + 20 u
= 60 u
60 u = 180
1 u = 180 ÷ 60 = 3
Number of cherries used to decorate all the small cakes
= 20 u
= 20 x 3
= 60
(c)
Number of cherries to decorate one large cake
= 5 u
= 5 x 3
= 15
Number of remaining large cakes that were decorated yet
= 35 - 8
= 27
Number of more cherries that Opal needed to decorate the remaining large cakes
= 27 x 15
= 405
Answer(s): (a) 10; (b) 60; (c) 405