1)
102+991= 1993
2)
Bunları sayabilirsin:
123,124,125,126,127,128,129,134,135,136,137,138,139,145,146,147,148,149,156,157,158,
159,167,168,169,178,179,189,234,235,236,237,238,239,245,246,247,248,249,256,257,258,
259,267,268,269,278,279,289,345,346,347,348,349,356,357,358,359,367,368,369,378,379,
389,456,457,458,459,467,468,469,478,479,489,567,568,569,578,579,589,678,679,689,789
3)
30+M+10M+4+40+N+10N+3=154
11M+11N+77=154
11(M+N)= 77
M+N=7
MN=61