adkikani
GMATNinja VeritasPrepKarishmaI would like to know what is it that a student misses to get to OA
in such HARD questions apart from skimming through the argument.
Goal of plan: To develop a prototype that makes clear difference between weeds and plants on basis of differences in shades of color.
Q type: I need to strengthen the implementation of above plan.
Quote:
(A) There is a considerable degree of variation in shade of color between weeds of different species
Nope we need to chop off weeds from plants, different types of weeds are not my areas of concern
Quote:
B) The shade of color of some plants tends to change appreciably over the course of their growing season.
It says shades of
some plants change
drastically ie in a large extent during the span of their growth.
So it does help new prototype machine to chop of plants from weeds.
Quote:
(C) When crops are weeded manually, overallsize and leaf shape are taken into account in distinguishing crop plants from weeds.
No mention how difference in color is useful in chopping off plants from weeds.
Quote:
(D) Selection and genetic manipulation allow plants of virtually any species to be economically bred to have a distinctive shade of color without altering their other characteristics.
As per me, the biggest reason missing out on this is: no mention of automatic weeding machine in OA, but I had to infer fair amount
of understanding from argument to link how selection and genetic changing of almost a large number of plants to allow to have
an unique shade of color of each plant
from one another . At least I could not infer to such an understanding level under time pressure.
What is the correct way of approach here?
Quote:
(E)]Farm laborers who are responsible for the manual weeding of crops carry out other agricultural duties at times in the growing season when extensive weeding is not necessary.
Totally out of scope
As you mentioned, the key is being able to differentiate between weeds and plants based ONLY on differences in shade of color.
All we know from (B) is that some plants will change color. We don't know whether that will make it
easier or
harder for the machine to differentiate between weeds and plants. It
might somehow make it easier but it also might not (i.e. perhaps the machine will have a hard time keeping track of the plants if their colors are constantly changing). Without further information, we can't tell whether (B) would hurt or help, so it must be eliminated.
(D) specifically tells us that we could use selection and genetic manipulation to give virtually ANY plant a a
distinctive (i.e. unique) shade of color. If every plant has a distinctive color, then it will be easy for the machine to identify the plants based on color alone. This clearly helps, so (D) is the best answer.
Sakshij0694
mikemcgarry GMATNinjaI am down to A and D and i find A more convincing then D to choose.
Please help me with this.
I invented a machine which differentiates Tshirts on the basis of color and helps me to pick one.
Now the more degree of variation of color, more will be the efficiency of the machine to choose correctly.
Example - I want a red shirt and the pool contains Red - Blue - Black which all are vibrant colors and easy to differentiate from.
However, If the pool contains Magenta,Purple, Dark Purple which narrows are variation of colors and this will lead to a subtle difference in choosing of an Tshirt for the machine and this will be a problem for the machine.
How to choose?
The same is the case for this machine here.
Thanking in advance.
Sakshij0694, sorry for the delay...
(A) only talks about the color variation among
weeds, not the color variation between weeds and plants.
(A) only tells us that there is wide
range of colors among weeds. That does not necessarily mean that the weeds colors are all distinctive and easy to differentiate (i.e. there still might be several shades close to purple, several shades close to orange, several shades close to green, etc.). In other words, having a wide range does not necessarily mean that weeds can be divided into a few discrete, easily separable color groups.
More importantly, it doesn't tell us anything about weeds vs plants. Is it easy to differentiate the weeds from the plants? Maybe the wide range of weed colors actually makes the machine's job harder... if there is a wide range of weed colors
and a wide range of plant colors, the machine might not be able to tell which is which. We might have red, blue, and black weeds and also red, blue, and black plants. This would obviously make it harder for the machine.
I hope that helps!