perplexus.info :: Numbers : No multiplication allowed

No multiplication allowed (Posted on 2013-10-17)

Below are four groups of three numbers each.

Combine the numbers in each group using only addition, subtraction, division, exponentiation, factorials and brackets so that each triplet yields the same result (there might be several solutions):

a. 2,7,8
b. 2,5,26
c. 3,11,15
d. 3,49,71

Inspired by "e pluribus unum" 2003 & 2004.

Submitted by Ady TZIDON

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Solution: (Hide)

Full solution A: 2*7-8 = 6 B: 2^5-26 = 6 C: 11-15/3 = 6 D: ((3!))/(71+49) = 720:120=6
3 out of 4 :
A: to get 20 seems impossible B: 26-(5-2)! = 20 C: 15+11-3! = 20 D: (71+49)/3! = 20
also
A: (8-7)^2 = 1 B: 26-(5^2) = 1 C: 15-11-3 = 1 D: to get 1 seems impossible

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
re: 3/4 of the way (In two ways) Want a hint?	Ady TZIDON	2013-10-22 18:54:24
3/4 of the way (In two ways)	Brian Smith	2013-10-22 11:33:05
Which one do you miss?	Ady TZIDON	2013-10-21 18:31:43
HINT: releasing the target number	Ady TZIDON	2013-10-19 18:48:29
re: Just one instance?	Ady TZIDON	2013-10-19 18:14:32
Just one instance?	Larry	2013-10-19 15:38:28
re: Not the way you intended.-(brackets)	Ady TZIDON	2013-10-17 19:10:09
Not the way you intended.	Jer	2013-10-17 15:48:58

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