Sarin and his coin bank part 44 (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 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.

You can read the posting on Sarin and his coin bank for the story of coin bank.

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

Upper primary school mathematics question UPQ433

Sarin and Hairu saved a sum of money each in their coin banks. If Sarin gave Hairu \$34, they would have same amount of money. If Hairu gave Sarin \$42, Sarin would have thrice as much as Hairu. How much did each of them have?

Solution:

Base on 1st “if”

They had same amount after Sarin gave Hairu \$34

Draw the model

Sarin had 2 × 34 = \$68 more than Hairu in the coin banlks

Base on the 2nd “if”

Sarin’s money was thrice Hairu’s money after got \$42 from Hairu

The model

From the model

2 units = 42 + 34 + 34 + 42

1 unit = 76

The amount of money Hairu had = 76 + 42 = \$118

The amount of money Sarin had = 3 × 76 – 42 = \$186