A family in Singapore part 3(Math Question)

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You can click here and read posting on A family in Singapore about Sarin’s family.

You should click and read posting on Sarin learns concept of ratio in school to understand mathematics concept of Ratio.

Upper primary school mathematics question UPQ115

Fatimah is 1/3 as old as Hairu now. In 6 years’ time, the ratio of Fatimah’s age to Hairu’s age will be 3: 5. How old is Hairu now?

 Solution:

                        The final ratio of the ages is Fatimah : Hairu = 3 : 5

                        After 6 years, the age different is still 6 years

                        2 units = 6

                        1 unit = 3

                        Hairu’s age today = 3 × 3 = 9 years old

  Alternative solution:

                                    (1U + 6) ÷ 3 = (3U + 6) ÷ 5

                                    5U + 30 = 9U + 18

                                    4U = 12

                                    1U = 3 years

                                    Hairu is 3 × 3 = 9 years old now

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