+0  
 
0
125
3
avatar

A number is formed by writing the numbers 1 to 30 in order as shown.


12345678910111213..........2930


Simeon removed 45 of these 51 digits leaving 6 in their original order to make the largest 6-digit number possible. What is the this number?

 Nov 27, 2019

Best Answer 

 #1
avatar
+1

n=123456789101112131415161718192021222324252627282930;s=0;p=0;cycle: s=s+(n%10);p=p+1;n=int(n/10);if(n!=0, goto cycle,0);print"Total Sum =",s;print"Total Num =",p

 

920,212 - is the largest such number.

 Nov 27, 2019
 #1
avatar
+1
Best Answer

n=123456789101112131415161718192021222324252627282930;s=0;p=0;cycle: s=s+(n%10);p=p+1;n=int(n/10);if(n!=0, goto cycle,0);print"Total Sum =",s;print"Total Num =",p

 

920,212 - is the largest such number.

Guest Nov 27, 2019
 #2
avatar+1078 
-1

We want the earliest digits to be the biggest. Let's start with 9 since that's the biggest number.

9_____

Now, the only numbers left we can use are 10, 11, 12, etc. all the way to 30.

30 is the biggest one, so let's use that next.

930___

BUT WAIT! There are no digits greater than 30. So let's do 29.

929___

Then 30

92930_

Here, we run into a problem. The last digit must be a single digit, but there is no single-digit remaining. 

If we choose two one-digit numbers in the beginning, then it will work out.

 

Obviously, 8 and then 9 is the best option.

89____

Then, since 30 cannot be used after these two numbers, we must use 29 and then 30.

Therefore, 892930 is the answer.

 

You are very welcome!

:P

 Nov 27, 2019
 #3
avatar
0

CoolStuff: Where does your number 892930 appear in the above sequence "leaving 6 in their original order"?

 Nov 27, 2019

62 Online Users

avatar
avatar
avatar
avatar