Select for x and y values that are jointly consistent with the info

Question

Although large mammals like elephants and whales tend to live longer than small ones like mice, larger breeds of dogs have shorter life spans, on average, than smaller breeds. A researcher studying the relationship between average body mass and average life span in breeds of dogs concluded that, for every 2 kilograms of body mass, life span is 1 month less. According to this conclusion, the average life span of a breed with an average body mass of x kg is y months less than the average life span of a breed with an average body mass of 10 kg.

Select for x and for y values that are jointly consistent with the information provided. Make only two selections, one in each column.

Select for x and for y values that are jointly consistent with the information provided. Make only two selections, one in each column.

GMATCoachBen · Accepted Answer

Video solution here (2:57):

https://www.youtube.com/watch?v=TXvfbBhtmtI
 
It's very helpful to notice and quickly translate this common RATIO wording:

For every ___, there were ___ translates to a ratio!

For example, "For every 2 men, there were 3 women": (M / W) = (2 / 3)

chetan2u · Answer

Select for x and for y values that are jointly consistent with the information provided. Make only two selections, one in each column. 
These type of questions are quite regular in focus edition test. The wording tells us that there are various possibilities for x and y, and just one of them is in option.

Only way to do this is by finding the  relation   between x and y.

x: Average life body mass
y: Difference in life span

For every increase in 2kg mass, life span decreases by 1 month. 
So (Mass increase)= M_1-M_2=2y  
Now mass is increasing from 10 to x, so 
 M_1-M_2=x-10=2y  
 x=2y+10

We can check options now. 
x is surely even and larger than y. 
so x can be 30 or 20
x=20: 20=2y+10 or y=5…..Not in options
x=30: 30=2y+10 or y=10…..Yes

Answer:
y=10
x=30

GMATCoachBen · Answer

loanpt0101  Do you know which exam number this one is from? Thanks!

loanpt0101 · Answer

I took this from the GMAT Prep Test Package (Test 3) on the mba(.)com
Thanks for your support.

GMAT745owner · Answer

so when avg mass is 10 kg, life span is 5 months less. 
when avg mass is 30, life span is 15 months less. 
so Y = 15 - 5 months, it's 10.

onlymalapink · Answer

i have no idea what happened here this has to be the most challenging question for me because instii cant understand after seeing the solution multiple times

Regor60 · Answer

First of all, recognize that the question is only asking about dogs, so ignore the preamble regarding large mammals.

Also, the question is poorly written and may confuse the reader, especially non native readers of English.

The question should be understood to state "for every INCREASE in mass" of 2kg, lifespan diminishes by 1 month.

This will properly point the reader to compare the weights of the two breeds by performing a subtraction of weights.

Dream009 · Answer

Under 2 mins idea y is obviously less than x. 
So take higher values of x - 35, 30, 25,20 - Now if I remove 10 from this it should be divisible by 2 and not give .5 (none of y options are in .5). Only 30 and 20 qualify.

Take 30. So 30-10 = 20 and decrease should be by 20/2 = 10 - Bingo matches. 
there is no 5 - the other pair is 20 & 5

Select for x and y values that are jointly consistent with the info

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Select for x and y values that are jointly consistent with the info

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