The number 55 was multiplied by a 55-digit number containing only ones. What is the sum of the digits of the product?
+129852 Discovering a pattern is always a useful thing to try in these problems
Note
55 * 11 = 605
55 * 111 = 6105
55 * 1111 = 61105
55 * 11111 = 611105
It appears that the sum = 6 + 5 + ( n - 2) * 1 where "n" is the number of 1s we are multiplying by
So...multiplying by 55 " 1s " gives the sum : 6 + 5 + (55 - 2) ^ 1 = 11 + 53 = 64
+373 Hey there, Guest!
So for this problem, we can actually do it in a simple way with smaller numbers:
55*11 = 605
55*111 = 6105
55*1111 = 61105
55*11111 = 611105
Do you see the pattern now?
Therefore: 6+(55-2)+0+5 = 64
Hope this helped! :)
( ﾟдﾟ)つ Bye
