+0

Using only for 4s and any symbol how can you make 10?

0
211
7

Using only four 4's and any symbol, how can you make 10?

Guest Jan 9, 2015

#6
+808
+5

Double factorial (aka semifactorial) is a mathematical operation in which one multiplies "every other" natural number up to a given number. A more precise definition is:

\$\$n!!=\prod \limits_{i=0}^{k}(n-2i)= n(n-2)(n-4)(n-6)...\$\$

Where k = (n/2) - 1

Or read more on the "Double Factorial" Wikipedia web page :)

Tetration  Jan 10, 2015
Sort:

#1
+808
+5

4 + √4 +√4 +√4

Technically speaking you've used two's since √x = 2√x

Tetration  Jan 9, 2015
#2
+91436
+5

4/4+4/4+4/4+4/4+4/4+4/4+4/4+4/4+4/4+4/4=10

Melody  Jan 9, 2015
#3
+808
0

Eureka!

4!!+(4+4)/4

Where "!!" stands for double factorial.

Tetration  Jan 9, 2015
#4
+91436
0

Hi Tetration

What does double factorial mean ?

Melody  Jan 10, 2015
#5
+26399
+5

.

Alan  Jan 10, 2015
#6
+808
+5

Double factorial (aka semifactorial) is a mathematical operation in which one multiplies "every other" natural number up to a given number. A more precise definition is:

\$\$n!!=\prod \limits_{i=0}^{k}(n-2i)= n(n-2)(n-4)(n-6)...\$\$

Where k = (n/2) - 1

Or read more on the "Double Factorial" Wikipedia web page :)

Tetration  Jan 10, 2015
#7
+91436
0

Thanks Tetration - I have never seen that before.

Melody  Jan 11, 2015

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