Raising Squares Part 1

Logic Level 1

\LARGE \square^{\square^{\square^{\square}}}

You are given that the numbers 1 , 2 , 3 , 4 1,2,3,4 are to be filled in the square boxes as shown above (without repetition), forming an exponent towers? . Over all 4 ! = 24 4!=24 possible arrangements, let S S be the minimal value that is achieved. How many arrangements of these numbers would produce the value of S?

Details and Assumptions

As an explicit example, a possible value of the resultant number is 2 3 1 4 = 8 \large 2^{3^{1^4}} = 8 .


The answer is 6.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

6 solutions

Tasneem Khaled
Aug 14, 2015

We know for sure that the minimum resultant that we can get is 1. So, keeping the number 1 in the huge box, the other three numbers 2,3,4 in the smaller boxes can be changed. So, 3! possible arrangements can be obtained where the resultant number is 1

What confused me is the the problem said "a minimum", not "the minimum".

Robert Mossman - 3 years, 11 months ago

-Robert Mossman Yeah, they should have specified that in the problem.

Tasneem Khaled - 3 years, 11 months ago
Rohit Udaiwal
Aug 12, 2015

It is for sure that the minimum number will be 1. So in 1st box .it'll be 1. And in rest 3 boxes 2,3,4can be arranged in 3! Ways that is six .so and. Is SIX

Right! It's just that simple. The key here is to identify that 1 power anything is 1.

Chung Kevin - 5 years, 10 months ago

The min. resultant is obviously one, so we need to calculate the number of ways we can get it (by using simple combinatorics):
_ * _ * _
3 * 2 * 1
=> n=6, where n is the number of ways to get 1.


Absolutely correct. Thank you!

Chung Kevin - 5 years, 6 months ago
Ervyn Manuyag
Nov 29, 2018

4-1=3!=6 that’s wassup

David Giarratana
Aug 20, 2018

If the lowest base is 1 1 , then it doesn't matter what the following powers are in the exponent tower; the result will still be 1. Therefore, S = 1 S=1 . This leaves 2 , 3 , 2, 3, and 4 4 . We may only choose one of these three digits for the three remaining positions, and once a digit is chosen, it may not be chosen again. As such, this is a straightforward combinatorics problem: 3 choices \rightarrow 2 choices \rightarrow 1 choice: 3 2 1 = 6 3 \cdot 2 \cdot 1 = 6

In other words, we have 3 possible digits and 3 slots to fill. When the number of slots to fill k k is the same as the number of digits available (without replacement) n n , the number of possible combinations is simply n ! n! .

Gia Hoàng Phạm
Aug 16, 2018

We sure that the minimum value is 1 because it's contains 1.Odd 1 out & we have ( 4 1 ) ! = 3 ! = 6 (4-1)!=3!=\boxed{\large{6}}

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...