you haven't take R=-S in the Case II of Statement 2
you have consider R=-4 and S=-2
1)
Case I:
-----r--0--s----t---
0 is midway between r & s.
Case II:
--0--r----s----t---
0 is not midway between r & s.
Not Sufficient.
2)
Case I:
Let's say r=-s;
r=-2; s=2 t =3
-----r--0--s----t---
|t-r| = |3-(-2)|=5
|t-s| = |3-(-2)|=5
0 is midway between r and s.
Case II:
Let's say r=-s;
r=-4; s=-2 t =-1; -s=2
-----r--s--t--0----(-s)
|t-r| = |-1-(-4)|=3
|t-s| = |-1-(2)|=3
0 is not midway between r and s.
Not Sufficient.
Combining both;
r=-2; s=2 t =3
-----r--0--s----t---
|t-r| = |3-(-2)|=5
|t-s| = |3-(-2)|=5
0 is midway between r and s.
Sufficient.
Ans: "C"
you have consider R=-4 and S=-2
fluke
punyadeep
Q)) On the number line shown, is zero halfway between r and s?
----r---- s---- t---
1). s is to the right of zero
2). the distance between t and r is the same as the distance between t and -s.
----r---- s---- t---
1). s is to the right of zero
2). the distance between t and r is the same as the distance between t and -s.
1)
Case I:
-----r--0--s----t---
0 is midway between r & s.
Case II:
--0--r----s----t---
0 is not midway between r & s.
Not Sufficient.
2)
Case I:
Let's say r=-s;
r=-2; s=2 t =3
-----r--0--s----t---
|t-r| = |3-(-2)|=5
|t-s| = |3-(-2)|=5
0 is midway between r and s.
Case II:
Let's say r=-s;
r=-4; s=-2 t =-1; -s=2
-----r--s--t--0----(-s)
|t-r| = |-1-(-4)|=3
|t-s| = |-1-(2)|=3
0 is not midway between r and s.
Not Sufficient.
Combining both;
r=-2; s=2 t =3
-----r--0--s----t---
|t-r| = |3-(-2)|=5
|t-s| = |3-(-2)|=5
0 is midway between r and s.
Sufficient.
Ans: "C"