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Comment on Nick, Mack and Chad
how about like this, since
let age of Mack be = M
let age of Nick be= M+9
let age of Chad be = (M+9)-12= M-3
Quantity A => Mack age in 2 years = M+2
Quantity B => Chad age 1 year ago = M-3
subtracting M from both quantities we get
QA QB
2 > -3
therefore QA> QB
hence A answer
That looks great. You made
That looks great. You made one small mistake though.
Chad's age 1 year ago = (M-3)-1 = M-4
alright thanks :)
So I have another way
Macks age: M
Nicks age: M+9
Chads age: (M+9)-12-1 ( Basically took nick's age which is m+9 , minus 12 )
I then solved M+9-12=0
M-3=0
M=3
I then substituted M for Qty A and B , and found Qty A to be greater and hence chose A
Perfect!
Perfect!
I thought on CQ's you couldn
Adding and subtracting
Adding and subtracting variables is perfectly valid when solving Quantitative Comparison questions. More here: https://www.greenlighttestprep.com/module/gre-quantitative-comparison/vi...
N = M+9
C = N-12
M = N-9+2 = N-7
C = N-12-1 = N-13
bigger quantity subtraction will yield smaller quantity
so (A)
Awesome! The tables work
Thanks, I used before the
Can we write everything
N=M+9
N=C+12
Then we can see M must be older than C and deduce that M's age in two years will clearly be greater than C's age a year ago. Or am I missing a concept somewhere?
That's a great approach! Pure
That's a great approach! Pure logic and number sense!
In the given question -
N = 9+M
C = 12-N
N# NICK M#MACK C#CHAD
if current age is 100 for M then -> M=100, N=109, C=97
if Mack's age after 2 years is 102, then N=111, C=99.
And Nicks 1yr ago age is 98. here 102>98 hence A.
How about this solution Brent? Is it a valid one?
Your equation C = 12 - N does
Your equation C = 12 - N does not match the given information.
We're told that Chad is 12 years younger than Nick.
So, for example, it could be the case that Chad is 3 and Nick is 15.
In other words, C = 3 and N = 15
When we plug these values into your equation, C = 12 - N, we get: 3 = 12 - 15, which is not true (12 - 15 = -3, not 3).
Likewise, it could be the case that Chad is 20 and Nick is 32.
However when we plug these values into your equation, we get: 20 = 12 - 32, which is not true.
The same applies to the values you are using: M = 100, N = 109, C = 97.
If we plug N = 109, C = 97 into your equation, we get: 97 = 12 - 109, which is not true.
If Chad is 12 years younger than Nick, then the correct equation is: C = N - 12
Does that help?
Thanks Understood!!