Wind speed

[gmat009]

When the wind speed is 9 miles per hour, the wind-chill factor

w is given by w = -17.366 + 1.19t, where t is the temperature in degrees Fahrenheit. If at noon yesterday the wind speed was 9 miles per hour, was the wind-chill factor greater than 0 ?
(1) The temperature at noon yesterday was greater than 10 degrees Fahrenheit.
(2) The temperature at noon yesterday was less than 20 degrees Fahrenheit.

OA is

SPOILER: E

, IMO

SPOILER: A

[just4kicks]

E is correct

[Shooter]

w = -17.366 + 1.19t

For my convenience I'll write this as

w = -17+t (rounded off)

For w to be greater than '0', 't' should be at least 18.

(I) t>10 INSUFF
(II) t<20 INSUFF

(I)+(II) still value can be 11 or 18 INSUFF

[bose]

imo e too
as 1 + 2 gives -6 <w<5