A family in Singapore part 49 (Math Question)


The blog postings are about the Singapore Math. The readers can learn from the postings about Solving Singapore Primary School Mathematics. The blog presenting the Math Concept, the Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids will able to acquire knowledge of dealing with the Math Modeling, the Math Problem Solving and 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 Ratio,  and Average Number.

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

Read the posting on Sarin learns concept of ratio in school to understand the concept of Ratio.

You should read the posting on Sarin learns Average Number, Percentage and Charting in school (Math Concept) to understand the concept of Average Number.

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

Upper primary school mathematics question UPQ423

The mass of Fatimah, Sarin and Hairu is in the ratio of 3 : 5 : 2. If Hairu’s mass is 24 kg, what is the average mass of three of them?


            The mass ratio of three of them

                        Fatimah : Sarin : Hairu = 3 : 5 : 2

                        Hairu is 24 kg

                        2 units = 24 kg

                        1 unit = 12kg

                        The mass of Fatimah = 3 × 12 = 36kg

                        The mass of Sarin = 5 × 12 = 60kg

                        The total mass of three of them = 24 + 36 + 60 = 120kg

                        The average mass of three of them = 120 ÷ 3 = 40kg

Altrernative solution:

            The mass ratio model of three of them


            Subdivide the each identical model block to 3

            The new mass ratio model for three of them


            To find average mass, redistribute the blocks equally to all three.


            From the model

            6 units = 24kg

            1 unit = 4kg

            The average mass = 10 × 4 = 40kg

            To note: we subdivide each block by 3, as there are 3 people’s mass. This is to make it able to redistribute the subblocks.         

More Questions on Ratio. Click here….

More Questions on Average Number. Click here….


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s