PSLE
Mr Loh used ⁵₇ of his money to buy 10 starfruits and 11 passion fruits. The cost of 5 starfruits was the same as that of 3 passion fruits. What was the most number of passion fruits that Mr Loh could buy with the money he had left?
Fraction of his money that he had left
= 1 - ⁵₇ 
= ²₇

Let the cost of 1 starfruit be 1 S.
Let the cost of 1 passion fruit be 1 P.

5 S = 3 P _(x2)
10 S = 6 P

Since Mr Loh wants to buy passion fruits with the money he had left, 10 starfruits will be substituted as 6 passion fruits.

⁵₇ of his money
= 10 S + 11 P
= 6 P + 11 P
= 17 P

⁵₇ of his money → 17 P
¹₇ of his money → ¹⁷₅ P
²₇ of his money → 2 x ¹⁷₅ P = 6⁴₅ P

Maximum number of passion fruits he could buy with the money that he had left = 6

Answer(s): 6