□ + □ = □ □ − □ = □ □ × □ = □ □ ÷ □ = □
Given that the integers 0 , 1 , 2 , … , 9 are to be filled in all the twelve square boxes above such that all four equations above are satisfied.
What is the minimum possible distinct number of integers used?
Details and Assumptions
You can use the same integer more than once.
You are not required to use all nine integers.
Each square box can only fill in exactly one digit.
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.
This is the exact solution I have! Thank you.
0 + 1 = 1 1 − 0 = 1 0 × 1 = 0 0 ÷ 1 = 0 It is clearly seen, that I have used only 2 distinct integers.
Great! What I did was to use 0's for all the boxes except for the second last one.
Log in to reply
Can't use just 0's as 0/0 is undefined
Log in to reply
Yes, that's why I said "except for the second last one". So I've used 0 ÷ 1 = 0 .
Can you not entirely use 0? Therefore only one integer
Log in to reply
I agree. As / the statement 0 is an integer an can satisfy every equation
As pointed out, 0/0 is undefined .
We are asked about distinct no of integers Basically we selected 0 as base for for every box and has replaced it with 1 in last box So therefore only 1 distinct no I.e. 1 is used instead of base no Therefore ans should be 1
I agree with Mark . If 0 is an integer You can satisfy all 4 equations with 0
Log in to reply
Unfortunately not. Because we cannot devide by zero, therefor 1 must also be used, and a minimum of 2 integers is the answer
Assume that there exists a single integer n that could satisfy every box. Take a look at row 4. n n = n. You cannot divide by zero, so the integer that satisfies this line cannot be zero. We can remove the n factor from the numerator of denominator of n n , giving us 1 1 = n, or just 1 = n. Therefore, if such a number n exists, it must be 1. However, if you replace n for 1 in n + n = n, the first line, this is a contradiction because 1 + 1 does not equal 1. Therefore, no such integer exists in which n could satisfy every box.
It can be proven that there exists a combination of 2 integers that can satisfy the equations by providing an example: 0 + 0 = 0; 0 - 0 = 0; 0 * 0 = 0; 1 / 1 = 1; Therefore, the minimum number of distinct integers is 2.
0 / 0 = 0 therefore only 1 integer required
Some one later notes that 0/0=undefined. Actually 0x0 = undefined. However it matters not since 1x1 = 1 Still only 2
What I did:
1 + 1 = 2
2 - 1 = 1
1 x 1 = 1
1 / 1 = 1
For completeness, since it asks for the minimum, we should show (state) that we cannot just have 1 integer.
Good point. The only way for the first line to have but a single integer is 0 + 0 = 0. But we can't using nothing but 0's since 0 / 0 is undefined. Therefore, a minimum of 2 integers are needed.
"Given that the integers 0,1,2,…,9"
Zero to nine is …….integers. Ten integers, if zero is included. But the problem allows all NINE integers. I guess zero doesn't count? Sort of a no account number. Please excuse the poor excuse for an attempt at mathematical humor.
Problem Loading...
Note Loading...
Set Loading...
One example is sufficient to support the fact of minimum of 2 distinct integers:
0 + 0 = 0
0 − 0 = 0
0 × 0 = 0
0 ÷ 1 = 0
Simplest set applied. The last row is flexible!
Answer: 2