+0  
 
0
2042
8
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If a, b, c, and d are replaced by four distinct digits from 1 to 9, inclusive, then what's the largest possible value of the difference a.b - c.d?

 

PLS HELP

 Dec 20, 2018
 #1
avatar+128475 
+1

a*b will be largest  when  a = 9  and b = 8  [or  vice-versa]

c*d  will be smallest when  c =2 and d =1  [ or vice-versa] 

 

So

 

The largest possible difference is

 

9 * 8  - 2*1  =

 

72  -  2  =

 

70

 

 

cool cool cool

 Dec 20, 2018
 #2
avatar
0

its not 70.....

Guest Dec 20, 2018
 #3
avatar+128475 
0

Sorry...I mis-read that as a multiplication....I think you wanted decimal values

 

The largest possible difference is

 

9.8  -  1.2   = 

 

8.6

 

 

cool cool cool

CPhill  Dec 20, 2018
edited by CPhill  Dec 20, 2018
edited by CPhill  Dec 20, 2018
 #4
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0

how???????

Guest Dec 20, 2018
 #5
avatar+128475 
+1

9.8 is the largest decimal that can be formed given the constraints  and 2.1 is the smallest....so....their difference will be the greatest

 

 

 

cool cool cool

CPhill  Dec 20, 2018
 #6
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0

Nevermind i put the wrong question the REAL Question is 

If a, b, c, and d are replaced by four distinct digits from 1 to 9, inclusive, then what's the largest possible value of the difference a.bc - 0.d?

 Dec 23, 2018
 #7
avatar+118609 
+2

What do you mean 'nevermind!'

You asked a question and CPhill went to a lot of effort to answer it for you.

The next thing for you to do is to say thank you! 

Melody  Dec 23, 2018
 #8
avatar+118609 
+2

Oh and you can appologize for wasting CPhills time too! 

Melody  Dec 23, 2018

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