Mark:
PASSWORD
93102
I am sure Stormy will show her appreciation in a tangible way!
The sum of the first two digits is exactly twice the sum of the last four. The smallest number that is the total of four different digits is 6
(0 + 1 + 2 + 3).
The sum of the first two digits, therefore, must be at least 12. The largest possible total for two different digits is 17 (8 + 9). Since the total of the first two digits is twice the sum of the last four, this total must be an even number.
So the possible totals for the first two digits are 12, 14, and 16.
But 16 (7 + 9) is impossible, because the total of the last four digits would have to be 8, and four different digits can't total 8 if one of them is 7 or 9.
Likewise, the total of the first two digits can't be 14 (5 + 9 or 6 + 8) because four different digits can't total 7 if one of them is 5, 9, 6, or 8.
The sum of the first two digits must therefore be 12. Since the sum of the last four digits is 6, none of the digits can be greater than 3. So the first two digits must be 9 and 3, in that order. The remaining digits must be 0, 1, and 2, in some order. The only order in which the sum of the middle three digits is twice the sum of the last two digits is 93102.
At the A2K Sports Store, Ping Pong Balls come packaged in boxes of 6, 15, and 20.
What is the largest number of ping pong balls that you can not purchase
By getting two boxes of 6, you have 12 ping pong balls. But you can not get 13 ping pong balls since no combination of 6, 15, and 20 adds up to 13.
So, in other words, what is the greatest number of ping pong balls that can NOT be made from 6, 15, and 20?
Due to my flight schedule, I regret I will not be around until Friday at the earliest.
<pauses>
Therefore here is Thursday's challenge:
I give you the answer; yes, give!
The answer to the problem is 45678.
You arrive at this by subtracting one number from another. The two numbers must contain the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. You must use each of these digits once, but only once.
E.g. nnnnn - nnnnn = 45678
What two numbers do you subtract to arrive at this answer