Answer: n; 160 =< n < 3796
Explanation:
Number of miles needed to claim Gold d has the range
{d; 2280022800 > d >= 96009600}
Greg goes 600600miles in a year
dGreg = 600600mi
Lower limit for a Gold status is 96009600
Thus, we find the lower limit of number of trips
n = d/dGreg
(d here is the lower distance per year to be covered in order to attain Gold)
n(lower) = 96009600/600600
= 159.8561 ~ 160 trips
n(higher) = 2280022800/600600
= 3796.24 ~ 3796 trips
In interval notation
n; 160 =< n < 3796