how many 7 digit number contain number 3 ?
"total 7 digit no . = 9 * 10 * 10 * 10 * 10 * 10 * 10 = 9000000 not containing 3 = 8 * 9 * 9 * 9 * 9 * 9 * 9 = 4251528 total 7 digit number contain 3 = 9000 - 4251528 = 4748472 answer : c"
add(subtract(subtract(const_1000, const_10), multiply(multiply(const_10, multiply(7, 7)), multiply(const_4, const_2))), const_10)