Question

Please help, I will MEDAL. I have some of it figured out.

Answer 1

2/10+2r=2
2r=1.8
r=.9
.9 is not an answer. What did I do wrong? @mathmale @AlexandervonHumboldt2

Answer 2

I changed it and did
2/10+2r=1
as in 1 is the total.
and then:
2r=.8
r=.4

.4 is an option, is that correct?

Answer 3

@Kainui is this correct?

Answer 4

Yes, it is correct! After 2 hours, Katherine sanded 2/10 of the cabinet by herself. We know that TOGETHER, both Katherine and Marina COMPLETE the job in those 2 hours. Therefore, Marine must have finished the other part of the cabinet, which is 8/10.
Multiplying 0.4 by 2 gets us 0.8 (pronounced eight tenths). Converting that into a fraction, we get 8/10. Therefore, B (0.4) is correct. :D

Answer 5

nvm @Kainui
Yay @ags2658
Thanks, I knew I had something weird and incorrect, I didn't know if it would equal 2 because together it took 2 hours, or 1 because it was an undetermined time. Thank you. :D

Answer 6

By the way, ''r'' would be 4/10 (which is 0.4). Therefore, ''2r'' is:
\[2 \times \frac{ 4 }{ 10 }= \frac{ 8 }{ 10}\]
If you need more explanations, let me know. :)

Answer 7

You are very welcome, Hailey-Graves. Glad I've helped! :D

Answer 8

omg @ags2658 That makes sense, okay, I will let you know, I have a few more problems on my Quiz, so you never know if I might need help with those, I usually figure them out after a little reminder of what I need to so though.