# Sarin participates in school anniversary event part 22 (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 to deal 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 Problem Solving.

Read the posting on Sarin participates in school anniversary event part 1 for story on school anniversary.

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

Upper primary school mathematics question UPQ460

Sarin was given some files and notebooks to give out as gifts during the school anniversary event. There were 280 more files than notebooks he received. After given our ¾ pf the files and 2/5 of the notebooks, 172 files and notebooks were left. How many files did he give away?

Solution:

Base on the initial condition and divide the notebooks to 5 portions and the files to 4 portions and draws the model

From the above model

1 unit = (5N +280)/4

After given out ¾ of files and 2/5 of notebooks and left with 172 files and notebooks

The model

From the above model

1 unit = 172 – 3N

Therefore

(5N + 280)/4 = 172 – 3N

5N + 280 = 4 × 172 – 4 × 3N

17N = 408

1N = 24

1 unit = 172 – 3 × 24 = 100

The number of file given out = 3 units = 3 × 100 = 300