how many odd integers from 1 to 100 ( both inclusive ) have odd number of factors ?
integers having odd number of factors will be perfect squares . odd numbers will have odd perfect squares . thus , the possible values for the perfect squares are : 1 , 9,25 , 49,81 and the corresponding integers are 1 , 3,5 , 7,9 ( more than 4 ) . thus c is the correct answer .
subtract(subtract(divide(divide(100, const_2), const_2), const_10), const_10)