Sarin’s family in Kluang part 23 (Math Question)

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The blog postings are about the Singapore Math. The readers can learn from the postings about Solving Singapore Primary School Mathematics. The blog presents the Math Concept, the Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn the skills of dealing with the Math Modeling, the Problem Sum from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper primary school math question on Problem solving.

Read the posting on Sarin’s family in Kluang about Sarin’s family venture in Kluang.

Challenge yourself with the question before look out for the given solution‼!

Upper primary school mathematics question UPQ570

Fatimah and Hairu were in Klung Mall with a total sum of $90. Fatimah spent twice as much as Hairu. The amount Hairu had left was $9 more than what he had spent. He had twice as much money left as Fatimah.

a.         How much money did Hairu spend?

b.         How much money did Fatimah have at first?

Solution:

upq570-1

            From the model,

            9U = 90 – 9 – 4.5 = 76.5

            1U = $8.5

            The amount spent by Hairu = 2 × 8.5 = $17

            The amount Fatimah had at first = 5 × 8.5 + 4.5 = $47

Alternative Solution:

            The amount that Hairu spent = 1U

            The amount that Hairu left = 1U + 9

            Since Fatimah spent twice as much as Hairu,

            The amount that Fatimah spent = 2U

            As Hairu left twice as much as Fatimah,

            The amount that Fatimah left = (1U+9) ÷ 2

            The total amount they had at first = $90

            1U + 1U +9 + 2U + (1U+9) ÷ 2 = 90

            4.5U = 90 – 9 – 4.5

            4.5U = 76.5

            1U = $17

            The amount that Hairu spent = 1U = $17

            The amount that Fatimah has at first

            = 2U + (1U+9) ÷ 2

            = 2 × 17 + (17 + 9) ÷ 2

            = $47

More Questions on Problem Solving. Click here…..

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