if m and r are two numbers on the number line,what is the value of r?
(1) the distance between r and 0 is 3 times the distance between 0 and m
(2)12 is halfway between m and r
I choose answer C
OA E
Number system problem
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- shovan85
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Please post the question in proper section. This is a DS question you posted in PS section.
Now come to question.
Given m, r two numbers in number line. r = ?
(1) We cannot say the value of r as both m and r can take multiple values satisfying the condition.
Not Sufficient
(2) 12 is the mid point.
So m = 13, r = 11 => 12 is mid
m = 10, r = 14 => 12 is mid
Not sufficient.
Combining both,
r = 3m (if both are on same side of zero i.e both are +ve or both are -ve) ... from (1)
(m+r)/2 = 12 ... from (2)
Thus m = 6 and r = 18.
But what will happen if m becomes -ve and r is +ve. Along with this if option 2 holds true then combining both will be invalid.
r = -3m (m is -ve and r is +ve) ... from (1)
(m+r)/2 = 12 ... from(2)
Thus, m = -12 and r = 36.
Hence, r can be 36 or 18. Thus not sufficient.
IMO
E
Now come to question.
Given m, r two numbers in number line. r = ?
(1) We cannot say the value of r as both m and r can take multiple values satisfying the condition.
Not Sufficient
(2) 12 is the mid point.
So m = 13, r = 11 => 12 is mid
m = 10, r = 14 => 12 is mid
Not sufficient.
Combining both,
r = 3m (if both are on same side of zero i.e both are +ve or both are -ve) ... from (1)
(m+r)/2 = 12 ... from (2)
Thus m = 6 and r = 18.
But what will happen if m becomes -ve and r is +ve. Along with this if option 2 holds true then combining both will be invalid.
r = -3m (m is -ve and r is +ve) ... from (1)
(m+r)/2 = 12 ... from(2)
Thus, m = -12 and r = 36.
Hence, r can be 36 or 18. Thus not sufficient.
IMO
E
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- rishab1988
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Prompt : r=?
1) Simplify 1 .
distance from 0 to r = 3 times distance from 0 to m. In other words, we are measuring distance (a positive entity),so sign does not matter.
In equation form |r|=3|m|.
r m
6 2
6 -2
-6 2
-6 -2
All these values and many infinite other value satisfy this condition. r=2,-2. Therefore, Insufficient.
2) (r+m)/2 =12
r+m =24
r could be 2,4,5 ( anything) and still satisfy this condition.
Therefore, insufficient
Combining 1 and 2
From 2 -> r+m=24
From 1 -> |r|= 3|m|
This equation is equivalent to 2 different equations -> r=3m ; r=-3m; -r=3m ( r=-3m); -r=-3m (r=3m) [ in inequalities it would be 4 different equations because the sign flips on multiplying by -ve]
Now First substitute r=3m in 2 to get 4m=24 -> m=6 and r= 3(6)=18
Then substitute r=-3m in 2 to get -2m=24 -> m=-12 and r =-3(-12)=36
Therefore r = 18 or 36. Two different values.
hence C also is insufficient.
Answer = E
1) Simplify 1 .
distance from 0 to r = 3 times distance from 0 to m. In other words, we are measuring distance (a positive entity),so sign does not matter.
In equation form |r|=3|m|.
r m
6 2
6 -2
-6 2
-6 -2
All these values and many infinite other value satisfy this condition. r=2,-2. Therefore, Insufficient.
2) (r+m)/2 =12
r+m =24
r could be 2,4,5 ( anything) and still satisfy this condition.
Therefore, insufficient
Combining 1 and 2
From 2 -> r+m=24
From 1 -> |r|= 3|m|
This equation is equivalent to 2 different equations -> r=3m ; r=-3m; -r=3m ( r=-3m); -r=-3m (r=3m) [ in inequalities it would be 4 different equations because the sign flips on multiplying by -ve]
Now First substitute r=3m in 2 to get 4m=24 -> m=6 and r= 3(6)=18
Then substitute r=-3m in 2 to get -2m=24 -> m=-12 and r =-3(-12)=36
Therefore r = 18 or 36. Two different values.
hence C also is insufficient.
Answer = E