Answer :
Solution:
1000
1000
+ 1000
..................
3000
+ 1100
.............
4100
............
1000
1000
+ 1000
..................
3000
+ 1100
.............
4100
............
adding 1000 3 times then came 1000+1000+1000=3000 and adding 1100 then get 3000+1100=4100