PSLE Erika baked a total of 26 large and small cakes in the ratio of 8 : 5. She decorated each cake with some grapes in the ratio of 9 : 5. She used a total of 312 grapes to decorate all the small cakes and 6 large cakes.
- How many small cakes did Erika bake?
- What was the number of grapes used to decorate all the small cakes?
- How many more grapes did Erika need to decorate the remaining large cakes?
(a)
Fraction of the cakes that were large ones =
88 + 5 =
813Number of large cakes
=
813 x 26
= 16
Number of small cakes
= 26 - 16
= 10
|
Large cakes |
Small cakes |
Total |
Number |
6 |
10 |
|
Value |
9 u |
5 u |
|
Total value |
54 u |
50 u |
104 u |
(b)
Number of grapes used to decorate 6 large cakes and 10 small cakes
= 54 u + 50 u
= 104 u
104 u = 312
1 u = 312 ÷ 104 = 3
Number of grapes used to decorate all the small cakes
= 50 u
= 50 x 3
= 150
(c)
Number of grapes to decorate one large cake
= 9 u
= 9 x 3
= 27
Number of remaining large cakes that were decorated yet
= 16 - 6
= 10
Number of more grapes that Erika needed to decorate the remaining large cakes
= 10 x 27
= 270
Answer(s): (a) 10; (b) 150; (c) 270