PSLE
Olivia baked a total of 20 large and small cakes in the ratio of 7 : 3. She decorated each cake with some cherries in the ratio of 3 : 2. She used a total of 96 cherries to decorate all the small cakes and 12 large cakes.

1. How many small cakes did Olivia bake?
2. What was the number of cherries used to decorate all the small cakes?
3. How many more cherries did Olivia 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 20
= 14

Number of small cakes
= 20 - 14
= 6

	Large cakes	Small cakes	Total
Number	12	6
Value	3 u	2 u
Total value	36 u	12 u	48 u

(b)
Number of cherries used to decorate 12 large cakes and 6 small cakes
= 36 u + 12 u
= 48 u

48 u = 96

1 u = 96 ÷ 48 = 2

Number of cherries used to decorate all the small cakes
= 12 u
= 12 x 2
= 24

(c)
Number of cherries to decorate one large cake
= 3 u
= 3 x 2
= 6

Number of remaining large cakes that were decorated yet
= 14 - 12
= 2

Number of more cherries that Olivia needed to decorate the remaining large cakes
= 2 x 6
= 12

Answer(s): (a) 6; (b) 24; (c) 12