PSLE
Mr Heng used ²₅ of his money to buy 10 mangosteens and 9 pomegranates. The cost of 5 mangosteens was the same as that of 4 pomegranates. What was the most number of pomegranates that Mr Heng could buy with the money he had left?
Fraction of his money that he had left
= 1 - ²₅ 
= ³₅

Let the cost of 1 mangosteen be 1 M.
Let the cost of 1 pomegranate be 1 P.

5 M = 4 P _(x2)
10 M = 8 P

Since Mr Heng wants to buy pomegranates with the money he had left, 10 mangosteens will be substituted as 8 pomegranates.

²₅ of his money
= 10 M + 9 P
= 8 P + 9 P
= 17 P

²₅ of his money → 17 P
¹₅ of his money → ¹⁷₂ P
³₅ of his money → 3 x ¹⁷₂ P = 25¹₂ P

Maximum number of pomegranates he could buy with the money that he had left = 25

Answer(s): 25