# Hairu and the numbers part 23 (Math Question)

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

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

Read also the posting on Sarin learns Symbol, Algebra and Equation in school (Math Concept) to understand the concept of Algebra.

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

Upper primary school mathematics question UPQ371

The average of 3 numbers is 3y. One of the numbers is y and another number is 5. Express the third number in terms of y in the simplest form.

Solution: The average of the 3 number is 3y

The total of the 3 number = 3 × 3y = 9y

The third number = 9y – y – 5 = 8y – 5