PSLE
Mr Choy used ⁴₉ of his money to buy 12 passion fruits and 9 mangosteens. The cost of 4 passion fruits was the same as that of 2 mangosteens. What was the most number of mangosteens that Mr Choy could buy with the money he had left?
Fraction of his money that he had left
= 1 - ⁴₉ 
= ⁵₉

Let the cost of 1 passion fruit be 1 P.
Let the cost of 1 mangosteen be 1 M.

4 P = 2 M _(x3)
12 P = 6 M

Since Mr Choy wants to buy mangosteens with the money he had left, 12 passion fruits will be substituted as 6 mangosteens.

⁴₉ of his money
= 12 P + 9 M
= 6 M + 9 M
= 15 M

⁴₉ of his money → 15 M
¹₉ of his money → ¹⁵₄ M
⁵₉ of his money → 5 x ¹⁵₄ M = 18³₄ M

Maximum number of mangosteens he could buy with the money that he had left = 18

Answer(s): 18