579 + 9999 = 10578
Using a calculator, which is available on all computers, the answer is easily found to be 10189.
10000 ; This may look to be wrong but you can have 0001 to 9999 which gives you 9999 different combinations of 4 digits, plus another one for 0000.
9999
Exactly as in the question 9999
9999 + 9 = 10008
579 + 9999 = 10578
197 + 1639 + 9147 + 6931 + 729 + 9999 = 28642
9998
13,666n
1 plus 9,999 equals 10,000. That is equal to 1,000 x 10.
simple 1+9999 = 10000 and 2+9998=10,000 and 3+9997 =10000 and there are 4999 of these combinations plus the number 5000 by istelf so 10,000*4999+5000 = 49,995,000
The answer to this sum is 2010198.
Using a calculator, which is available on all computers, the answer is easily found to be 10189.
9999 = 3^2 x 11 x 101
10000 ; This may look to be wrong but you can have 0001 to 9999 which gives you 9999 different combinations of 4 digits, plus another one for 0000.
From 1000 to 9999 (inclusive) there are 9999 - 1000 + 1 = 9000 integers. Half of which are even, half of which are odd. So the answer is 9000/2 = 4,500.