Answer:
18 miles
Step-by-step explanation:
Let's call it's initial elevation x. Because it descends 3 miles, we now have x - 3. The question says it is now 15 miles above sea level, or x - 3 = 15, and adding 3 to both sides shows that x = 18 miles.
Step-by-step explanation:








The answer is C.
120 * 1.75 = 200
5 times 0 = 0
5 times 2 = 10 carry the 1
5 times 1 = 5 + 1 = 6
7 times 0 = 0
7 times 2 = 14 carry the 1...
7 times 1 = 7 + 1 = 8
1 times 0 = 0
1 times 2 = 2
1 times 1 = 1
add it all together and you get 200.