Sarin’s family attend concert at the Esplanade Part 27 (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, the Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn how to deal with the Math Modeling, the Math Problem Solving and the Problem Sum from Lower Primary School to Upper Primary School level. This posting is an upper primary school math question on Ratio and Problem Sum.

The story on Sarin’s family attend concert at the Esplanade you can read postings on Sarin’s family attend concert at the Esplanade in Welcome category and Sarin’s family attend concert at the Esplanade Part 2 (Math Question).

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

Upper primary school mathematics question UPQ492

In the Esplanade Library, the ratio of the number of men to the number of women at was 2 : 3. After some time, 60 more men came and 30 women left. In the end, there were 20 more women than men. Find the number of women at the Esplanade Library in the end.

Solution:

There were 20 more women in the Esplanade Library than men at the end

The model,

There are 60 more men came in and 30 women left the Esplanade Library, by removing 60 men and adding 30 women to the above model will give the men to women ratio of 2 : 3

The final model,

From the model,

1P = 60 + 20 + 30 = 110

The number of women at the Esplanade Library in the end = 3 × 110 – 30 = 300

Alternative solution:

The initital ratio:

Men : Women = 2 : 3

60 men came in and 30 women left

At the end, Women was 20 more than Men

Men ==> 2U + 60

Women ==> 3U – 30

The different = 20

3U – 30 – 2U – 60 = 20

1U = 110

The number of women at the end = 3 × 110 – 30 = 300