90-7 =83 degrees
height = 3 miles
divide 3 by the cos of 83 degrees
3/cos(83) = 24.6165
rounded to nearest mile = 25 miles
{1,2,3,4,5,6,7,8}= Sample space
Assuming the +'s are actually x's 1/2 of 3 is 1.5 and 1.5 divided by 7 is 1.5/7.(answer is 1.5/7) hopefully I'm right.