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the sum of the digits of a two digits number is 5. the digits are interchanged, when 27 is added to it. find the number.

Guest Apr 17, 2015

Best Answer 

 #1
avatar+93691 
+10

this is a neat little simultaneous equation question :))

 

Let the number be 10a+b  so it will look like ab

a+b=5      (1)

 

10a+b+27=10b+a

9a+27=9b

a+3=b      

a-b=-3      (2)

 

(1)+(2) 

2a=2

a=1

b=1+3=4

So the original number is 14

 

checking:

14+27=41  that is good

1+4=5   that is good too   :)

Melody  Apr 17, 2015
 #1
avatar+93691 
+10
Best Answer

this is a neat little simultaneous equation question :))

 

Let the number be 10a+b  so it will look like ab

a+b=5      (1)

 

10a+b+27=10b+a

9a+27=9b

a+3=b      

a-b=-3      (2)

 

(1)+(2) 

2a=2

a=1

b=1+3=4

So the original number is 14

 

checking:

14+27=41  that is good

1+4=5   that is good too   :)

Melody  Apr 17, 2015
 #2
avatar+90084 
0

I always like these, too, Melody......good job   !!!!

 

 

  

CPhill  Apr 17, 2015
 #3
avatar+93691 
0

Thanks CPhill 

Melody  Apr 17, 2015

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