1111 = 5
Add all the numbers, 1+1+1+1 = 4 ...................(1)
Mulltiply all the numbers, 1x1x1x1 = 1 ............(2)
(1) + (2)
4+1 = 5
Similarly,
For,2222
2+2+2+2 = 8
2×2×2×2=16
8+16 = 24
3333,
3+3+3+3 = 12
3×3×3×3=81
12+81=93
So, 5555,
5+5+5+5 = 20
5x5x5x5 = 625
625+20 =645 Ans.