Math puzzle driving me crazy

Miscellaneous and Personal Stuff I Must Share
1

Received this at work - the sender says he knows the answer, and it’s completely possible using the rules set down:

You have the numbers 1, 7, 7, 7 and 7 (that’s four sevens and a one).
You may use any of the conventional mathematical operators (add,
subtract, multiply and divide) and you may use brackets. You do NOT need
to do anything tricky like ‘sticking’ numbers together (such as making
two 7s into 77). Your target is to make exactly 100. This is not a trick
question.

I’ve resigned myself to not solving it myself, so don’t feel that I’m cheating, and I will not pretend that the answer is my own. Any ideas? I’m going nuts over it.

2

[spoiler]

1+ 7 x 7 + 7 x 7

or to be more clear 1 + (7 x 7) + (7 x 7) [/spoiler]

3

NO ! :smack: i’m idiot. ignore me.

4

yeah, I did the exact same thing.

5

Here’s a trick answer that’s almost certainly cheating:

Turn two of the 7s upside down so that they look like Ls.
Then L + L + [(7/7) – 1] = 100.

6

(7/7)+((7+7)*7)+1

You have just witnessed an amazing feat ladies and gentleman, as I am president of the “Bad Math Club.” Just yesterday I had to ask someone how to do X = 2% * Y for Y. I am amazed, myself.

7

Cheating or not, I think that is brilliant, Thudlow.

8

But that’s 5 7’s, not 4.

9

ROTFL that’s 5 sevens.

See, I knew it was too good to be true :slight_smile:

I am no longer amazed and can now retreat back to the Land Without Math.

10

Too many sevens, I think.

11

ZipperJJ your solution has one 7 too many…

12

I could do it with five sevens.

1+(77)((7+7)/7)

Still working on the four seven version.

13

I swear ZipperJJ’s post wasn’t there!

14

(7+7) * (7+(1/7))

15

Yay Struan!!!

16

/applause Struan

That was driving me mad, thanks for putting me out of my misery.

17

I think he’s got it.

18

So is someone going to cough up the $7 + $7 +$1 for Struan’s membership?

19

my hat’s off to you, Straun !
now i can move on to other ways to embarrass myself …

20

You guys need to be more rational:

(7 + 7)(7 + 1/7) = 100

Stranger