PSLE
Marion baked a total of 30 large and small cakes in the ratio of 7 : 3. She decorated each cake with some cranberries in the ratio of 3 : 2. She used a total of 288 cranberries to decorate all the small cakes and 10 large cakes.

1. How many small cakes did Marion bake?
2. What was the number of cranberries used to decorate all the small cakes?
3. How many more cranberries did Marion need to decorate the remaining large cakes?

(a)
Fraction of the cakes that were large ones = ⁷_{7 + 3} = ⁷₁₀

Number of large cakes
= ⁷₁₀ x 30
= 21

Number of small cakes
= 30 - 21
= 9

	Large cakes	Small cakes	Total
Number	10	9
Value	3 u	2 u
Total value	30 u	18 u	48 u

(b)
Number of cranberries used to decorate 10 large cakes and 9 small cakes
= 30 u + 18 u
= 48 u

48 u = 288

1 u = 288 ÷ 48 = 6

Number of cranberries used to decorate all the small cakes
= 18 u
= 18 x 6
= 108

(c)
Number of cranberries to decorate one large cake
= 3 u
= 3 x 6
= 18

Number of remaining large cakes that were decorated yet
= 21 - 10
= 11

Number of more cranberries that Marion needed to decorate the remaining large cakes
= 11 x 18
= 198

Answer(s): (a) 9; (b) 108; (c) 198