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: 
Heh, how about:

```
(3 XOR 5) x (3 XOR 7)

```

... yes, yes, I know XOR's not allowed. Poor XOR. Nobody ever invites him.
please check it 

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