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primary 5 | Maths | Whole Numbers

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##### Sweet Strawberry

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Appreciate if can provide steps to this question.

Date Posted: 7 months ago
Views: 60
J
7 months ago
Trick is that the total number of pens remained the same.

At first, blue pen = 5 units
Red pen = 1 unit
Total = 6 units

After, red pen = 2 units
blue pen = 1 unit
Total = 3 units

Since total number of pens is the same, we make the number of units the same.

3 units x 2 = 6 units

So in the end,

Blue pen = 1 units x 2 = 2 units
Red pen = 2 unit x 2 = 4 units

So you can see that number of blue pens decreased by 3 units. Number of red pens increased by 3 units

3 units = 21 pens
1 unit = 21 pens ÷ 3 = 7 pens

Number of red pens in the box at first = 1 unit = 7

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