Question

In a box leah has 6 red pens and 7 blue pens. if there are a 42 blue pens, how many red pens would she have?

Answer 1

Leah would have 35 red pens.

Let's use a tree diagram to solve this problem.

There are 6 red pens and 7 blue pens in the box, and we know there are a total of 42 blue pens.

So, let's assume that Leah takes out 1 blue pen and we are left with 41 blue pens and the rest of the pens.

If we continue this process, we can see that for every blue pen Leah takes out, there will be 1 less blue pen and 1 more red pen.

Since there are 7 blue pens in the box and we started with 42 blue pens, Leah would have 42 - 7 = 35 red pens.

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