How many positive integers less than 1000 have at least one digit of 0 and at least one digt of 1?
10 , 100 , 101 , 110 , 120 , 130 , 140 , 150 , 160 , 170 , 180 , 190 , 201 , 210 , 301 , 310 , 401 , 410 , 501 , 510 , 601 , 610 , 701 , 710 , 801 , 810 , 901 , 910 >>Total =28 such integers.
