Not being able to understand the question and concept

#1

how did we get sample op from sample 1p i can understand it can’t be simple addition that i kow but how did we get sample op

#2

4
1 0 2 9
5
3 4 5 6 7

iterate through array (in reverse order from right to left) and sum=arr1[i]+arr2[i]
and also make a variable carry to store carry
sum =sum%10
carry =sum/10;
in this way iterate and store your ans in an array
at end print the array