Friday, April 30, 2010

April 2010 Brain Teaser Answer

Using all the digits from 0,1,2...9, form two 5-digit numbers so that their sum is the

a)smallest sum:   34047


One example:  20468 + 13579
Another example is: 10468 + 23579
 
You cannot have a leading zero (the number cannot start with a zero) so for the least sum, start with 1 for the first number and 2 for the second number. Then make 0 the second digit of one of them and 3 the other second digit.  Then continue with 4 and 5 and so on.

b)greatest sum: 183951

One example is: 97531 + 86420
Another example is: 87531 + 96420

For the greatest sum: First digits 8 or 9, Second digits 6 or 7 and so on.

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