missionmba wrote:PS Practice test question #9

i go with 1 and 2

we shud be concerned with only
0< 1-c/d <1

from the above inequality its clear that the value of
1- c/d should between 0 and +1

we know D>0 if C<0 the the equation 1- C/D will become greater than 1

hence should be C>0........................1

C/d<1
which we know d>0 and C cant be <0 both C,d>0
and 1-c/d<1
if c/d >1 then 1-c/d will always be <0 ( as the equation will result in a negative value...)
hence c/d should always be less than 1................................2

c^2+d^2 >1

we know d>0 but C can be negative as well

but if C<0 then the equation 1-c/d will >0 which is wrong ... 3

hence only 1 and 2 are always true...

hope that helps...

0< 1-c/d <1
0<c/d<1
given d>0 you can answer I and II

for c^2 + d^2 > 1 take a counter-example with c=1/4 and d=1/3 for example