Question

If E partitions CD by a ratio of 1/8, then which of the following could be the location of E?

Answer 1

-7
-5
-3
-1

Answer 2

We're going to need a bit more information about CD!

Answer 3

ok i attach the line

Answer 4

\

Answer 5

@whpalmer4

Answer 6

what is the length of CD?

Answer 7

16?

Answer 8

@whpalmer4 is that right ?

Answer 9

Let me look!

Answer 10

ok

Answer 11

yes, that appears to be correct.

Answer 12

are you sure that 1/8 is the ratio?

Answer 13

yes it is

Answer 14

because if it is, we won't land exactly on any of those numbers in the answer choices

Answer 15

did you see the picture i attached?

Answer 16

we have 16 units to divide into 1+8=9 parts, and then we'll take 1/9 of those parts from an endpoint to find our partition.

Answer 17

ok so how do i do that?

Answer 18

possibly the problem expects you to choose -7 as your answer, but that isn't strictly speaking correct. partition CD by 1/8 means that CE and ED have the ratio 1:8, which means we must chop CD into 9 equal parts, and place E 1 part toward D from C.

CD goes from -9 to +7 in your diagram, which is a total of 16 units. 16/(8+1) = 16/9 and neither 1*16/9 nor 8*16/9 is a round number, yet all the answer choices are round numbers.

Answer 19

16/9 = 1.77777777... so if we add -9 + 1.777777... we get -7.22222... which is close to -7, but not the same. But all the other answers are even further removed from the 1/8 point, so that's the best of the bunch, I suppose.

Answer 20

ok that makes sense maybe were supposed to round

Answer 21

If the ratio was 1/7, then we could do the problem correctly.

CD is 16 units long, divided into 1+7=8 parts gives us 2 units per part. Our ratio calls for us to go 1 part = 2 units toward D from C, so -9 + 2 = -7 and that is exactly what one of the answer is. That's what made me ask if you had copied the problem correctly (you had, but I think the problem is incorrect. It happens much more often than it should, given what textbook publishers charge!)

Answer 22

Anyhow, do you at least understand how I worked the problem?

Answer 23

yes i do thank you so much ill put -7 but ill eamil my teacher

Answer 24

Yes, that would be good. If they insist that the problem is correct as written, let me know and I will supply you with some problems for them that demonstrate the flaw in their understanding :-)