Question: Using operators plus, minus, multiplied by and divide by, and as many brackets as you want, can you do a formula which uses 3, 3, 5 and 7 to make 24? 

Each number must be used and can only be used once (so there will be two 3's).

So, for example, (3x7)+3 makes 24, but this isn't valid because the 5 wasn't used.

I don't know if this is possible, btw! It's in a game I'm playing.

Answer: 
How about: 

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>  3 + 3 + 5 + 7 **+ 6** = 24
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Explanation:

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>  Each number must be used and can only be used once, **but the rules don't say *other* numbers cannot be used**!
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please check it 

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>  $(3\*3\*5)-(7\*3) = 45-21 = 24$
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