Answer:
10
Step-by-step explanation:
20/2=10
10+10=20
17
3.250 liters of softener because you have to jump three times according to the ladder method.
Moving up would add to the Y value. Moving to the left subtracts from the X value.
The answer would be: (X,Y) — (x-3, y + 5)

<u>Mona starts from 68th stone</u>
<u>She jumps</u><u> </u><u>23</u><u> </u><u>stones</u><u> </u><u>ahead</u><u> </u>
<u>Then</u><u> </u><u>she</u><u> </u><u>jumps</u><u> </u><u>28</u><u> </u><u>stones</u><u> </u><u>back</u>

<em>Her final position=?</em>




- To find how much stones she is ahead or back we will Subtract 63 from 68 which was her initial position.

So, Mona will be <em><u>5</u></em><em><u> </u></em><em><u>stones</u></em><em><u> </u></em><em><u>behind</u></em><em><u> </u></em><em><u>from</u></em><em><u> </u></em><em><u>the</u></em><em><u> </u></em><em><u>starting</u></em><em><u> </u></em><em><u>stone</u></em><em><u>.</u></em>
☯️Hence, Option C is correct
A: -15/5 degrees Celsius
B: -15/5=3 degree Celsius
every 5 weeks it change -15°c
so each week it changes -3°c