Sum of largest digit in 4digit number of 4 number
Answers
Step-by-step explanation:
4444+4444+4444+4444=17776
Solution:-
To find sum of all 4 digit positive numbers with non zero digit (1,2,3 and 4), we have to find the sum of all numbers at first, second, third and fourth places.
Let us find the sum of numbers at the first place (thousand's place).
In the 3024 numbers formed, we have each one of the digits (1, 2, 3, 4, 5, 6, 7, 8, 9) 336 times at the first place, second place, third place and fourth place.
Sum of the numbers at the first place (1000's place) :
= 336(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9)
= 336 x 45
= 15120
Sum of the numbers at the second place (100's place) :
= 336(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9)
= 336 x 45
= 15120
Sum of the numbers at the third place (10's place) :
= 336(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9)
= 336 x 45
= 15120
Sum of the numbers at the fourth place (1's place) :
= 336(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9)
= 336 x 45
= 15120
15120 is the sum of numbers at thousand's place. So 15120 is multiplied 1000.
15120 is the sum of numbers at hundred's place. So 15120 is multiplied 100.
15120 is the sum of numbers at ten's place. So 15120 is multiplied 10.
15120 is the sum of numbers at unit's place. So 15120 is multiplied 1.
Note :
The method explained above is not only applicable to find the sum of all 4 digit positive numbers with non zero digit. This same method can be applied to find sum of all 4 digit numbers formed using any four digits in which none of the digits is zero.