A builder builds a hundred houses how many no 9's does he need for the door numbers??

Question

its 20!! work it out

Answer 1

are the houses sequentially numbered? At what number do they start? Need more information.

you could build a thousand houses w/o any #9s if you neglected any numbers w/ nines. the key is are they sequential?

given that they are sequential there is a big gap in answers if you started at 1 versus 899

Answer 2

The answer is not possible. Trick question.

Builders do not build a 100 houses in a row.

They are in a sub-division. <}:-})

Answer 3

If he begins number a "1" and ends at "100" he needs 20. Here are the house numbers:

9

19

29

39

49

59

69

79

89

90

91

92

93

94

95

96

97

98

99

Answer 4

There is no way to work this out, number does not start at 1.   It could start at 199900 or at 1.   100 homes also do not have to be on the same street, the numbers can be repeated.

Answer 5

10

Answer 6

19

9 19 29 39 49 59 69 79 89 90 91 92 93 94 95 96 97 98 99