how many seven - digit numbers that do not contain the digits 2 or 9 are there ?
"we can have 7 digits ( 1 , 3,4 , 5,6 , 7,8 ) for the first place ( million ' s place ) . and similarly 8 digits for hundred thousands , ten thousands , thousands , hundred ' s , tenth ' s and unit digit . ( 0,1 , 3,4 , 5,6 , 7,8 ) so in total 7 * 8 * 8 * 8 * 8 * 8 * 8 = 1835008 hence e"
multiply(multiply(multiply(const_10, const_10), subtract(const_10, const_1)), 9)