Found this problem: And the correct answer is:
**2**

Counter-Argument: What if

- Red Box : Green Balloons
- Yellow Box: Blue Balloons
- Blue Box: Red Balloons
- Green Box: Yellow Balloon

Thus, we need to open minimum of 3 boxes to know what is contained in all the boxes"

Doesn't that makes sense?

I know the question asked for MINIMUM NUMBER OF BOXES, and if you'll look at the explanation, they have proved their answer. But what if there happens to be the case mentioned above?

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1 vote

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## Comments

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TopNewestWhy blue box can not contain yellow balloon? If you'll check the case 1 in the explanation, they have taken the assumption of "swapping the balloons"

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Because the green box already contains yellow balloons, so the blue box cannot contain yellow balloons (again).

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How can you be sure, what if green box contains red balloons? Don't you think in order to

verifywe need to check the third box?Log in to reply

The answer is still 2.

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If the order is Red Box : Green Balloons Yellow Box: Blue Balloons Blue Box: Red Balloons Green Box: Yellow Balloon

And the order of opening boxes is

1st: Red Box 2nd: Yellow Box

Then there is no way to figure out which colored balloon is present in Blue and Green box. Because it creates possibilities:

Blue box can contain : Yellow balloon or Red Balloon Similarly Green box can contain: Yellow balloon or Red Balloon

That's the only doubt I have.

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Suppose you open the first box labeled colour X, and it shows that it contain balloons of colour Y, then open the second box with label colour Y. That way, you don't have to open the third box to figure out all the remaining colors.

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No, it's still 2.

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