SOLUTION: Multiple Choice. Selma threw a ball 10 feet up in the air out of a window, then it fell 25 feet down to the ground. Which expression best represents the total distance the ball tra

Algebra ->  Absolute-value -> SOLUTION: Multiple Choice. Selma threw a ball 10 feet up in the air out of a window, then it fell 25 feet down to the ground. Which expression best represents the total distance the ball tra      Log On


   



Question 1208193: Multiple Choice. Selma threw a ball 10 feet up in the air out of a window, then it fell 25 feet down to the ground. Which expression best represents the total distance the ball traveled?
a. 10 − 25
b. 10 + |−25|
c. 25 − 10
d. 25 + |−10|

Found 3 solutions by josgarithmetic, ikleyn, math_tutor2020:
Answer by josgarithmetic(39623) About Me  (Show Source):
You can put this solution on YOUR website!
Two of them but probably the best choice is b.

Answer by ikleyn(52832) About Me  (Show Source):
You can put this solution on YOUR website!
.

To solve this problem correctly, you should keep two ideas in your mind.


First idea is that the traveled distance is the sum of partial traveled distances.

Second idea is that traveled distance is always positive.


With these two ideas in your mind, you quickly guess that the right options/formulas are (b) and (d).


But the author wrote them in over-complicated form.
More simple form is 10 + 25. It expresses the same conception, the same idea
and the same final value in adequate simple form.


So, (b), (d) and (10+25) express the same conception, the same idea
and the same final value of 35 feet for the total traveled distance.


Also, in this problem a coordinate system is not introduced and is not defined.
Therefore, using negative values in the problem's description makes no sense,
at all, and is not connected in meaning with the problem.

This problem, as it is worded in the post, looks like a lame horse with three legs,
and the entire composition looks as if some words in it are swallowed and missed.


//////////////////////////


Looking in this post, I clearly see that somebody, who has no adequate mathematical education
and has no skills to teach, tries to perform a role of a teacher or a composer of Math problems
and creates crazy idiotic assignments.

It is totally crazy idea to teach Math without knowing Math, from the very beginning to the very end.



Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

Answer: Option B


Think of a vertical number line (example: y axis).
Moving up this number line means we're involving positive values.
Moving down means we use negative values.
+10 means "go up 10 feet".
-25 means "go down 25 feet".
Absolute value represents distance from zero on the number line.
Negative distance doesn't make sense, so the absolute value turns a negative value positive.
|-25| = 25

So,
10 + |-25| = 10 + 25 = 35 feet is the total distance the ball travels.

In other words,
10 feet up + 25 feet down = 35 feet total