If mv<pv<0, is v>0?

(1) m<p
(2) m<0

GMAT PREP says the correct answer is D. But I thought it was B, I dont understand how 1 makes it sufficient.

(1) m<p and mv<pv<0
if m and p are negative values (ex. m=-5, p=-3) then v must be positive whatever is its value
if m and p are positive values (ex. m=3, p=5) then v must be negative if we have mv<pv<0
if m is negative and p is positive (ex. m=-2, p=3) then it is inconsistent with mv<pv<0

So I dont understand where I making the mistake

(2) m<0 and mv<pv<0

Here if m<0 then if we want mv<pv<0, v must be positive. SUFFICIENT

Thanks

(1) if m<p, mv<pv<0 will only hold if V is +ve and M and P are -ve. For other two cases that you mentioned mv>pv so they are not valid.

Hence, for mv<pv<0 V to hold, V has to +ve. So (1) is sufficient.

GMAT 2007

Luci, you were on the right track with your process, but you didn't actually work out the numbers, so you didn't notice that some of them were inconsistent with the given condition (mv<pv<0). I love trying numbers as a technique, but make sure you follow through just a bit more on the calculations.

If you had, you would have seen:
ex. m=3, p=5, and let's make v =-2
mv = -6
pv = -10
-6<-10<0
Which is not true, so that combination is invalid - I can't use it to test the statement. The only way to make it work would be to make p less than m, but statement one gives the condition m<p, so I can't do it.