# Sarin and his mother Part 2 (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 presenting the Math Concept, Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn the skills to deal with Math Modeling, Math Problem Solving and 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 Problem Sum.

To read also the posting on Sarin learns concept of ratio in school to understand the concept of Ratio.

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

Upper primary school mathematics question UPQ342

Sarin is 12 years old now. His mother is 4 times as old as he is. What will be the ratio of Sarin’s age to that of his mother’s age in 6 years’ time?

Solution:

Drawing the math model for this year age

From the model

1 unit = 12 years

Another 6 years, this is half a unit of the above model

You can redraw the above model base on 1 unit as 6 years

To obtain the Ratio, count the number of units

Sarin’s age after 6 years = 3 units

Mother’s age after 6 years = 9 units

The ratio of Sarin’s age to that of his mother’s age in 6 years’ time = 3 : 9 = 1 : 3

Alternative Solution:

The age of Sarin this year = 12

The age of his mother this years = 4 × 12 = 48

The age of Sarin after 6 years =12 + 6 = 18 years old, and,

The age of his mother after 6 years = 48 + 6 = 54 years old

The ratio of Susan’s age to that of her father’s age in 6 years’ time is 18 : 54 = 1 : 3