Quiz 2 of Intro to adding negative numbers

 Hello All, If I am wrong about the following I apologize in advance and would appreciate your assistance in understanding this question more clearly.

There is a question on Quiz 2 of Intro to adding negative numbers that asks for the distance between the Earth's surface and the upper edge of the earth's atmosphere. The answer given is the absolute value of v-b. Isn't the absolute value of v-b in this question the distance between the sun and the surface of the earth? Shouldn't the question ask what is the distance between the sun and the surface of the earth? This would then fit the logic of the absolute value of a-b? Thank you for helping me out with this.