math DS questions: need help solving

[sailaxman]

hi guys, below are few DS questions i had trouble answering,,,,,,,,,,need help.....thanks in advance


159) In xy coordinate plane, line l and line k intersect at point (4, 3). Is product of the slopes negative? C
a. Product of x intercepts of lines l and k is positive
b. Product of y intercepts of lines l and k is negative

OA: C

157) If ab ≠ 0 and (-a, b) and (-b, a) are in the same quadrant, is (-x, y) in this quadrant?
a. xy > 0
b. ax > 0

OA: C


198) All the clients that company x had at the beginning of the year remained with the company for the whole year. If Company x acquired new clients during the year, what was the ratio of number of clients that Company X had at the end to no. of clients that Company X had at the beginning of the year?
a. Ratio of no. of clients that Company X had at beginning of last year to no. of new clients that it acquired during the year was 12 to 1.
b. Company X had 144 clients at beginning of last year

OA: A

[neerajkumar1_1]

159)
check the link below:
https://www.beatthegmat.com/xy-coordinate-t30811.html
also do a search before u post... u will find many posts answering the same question...

198) let the number of people at the beg = x
let the number of new clients acquired = a

number of clients at the end of the year = x + a

question asks the ratio of number of clients that Company X had at the end to no. of clients that Company X had at the beginning of the year
i.e (x + a )/x = 1 + a/x

so if we get a/x we can get our answer...

Statement 1) gives u x/a... which can be converted to a/x
sufficient

statement 2) does not give u info on the new clients...
insufficient...

Pick A

[neerajkumar1_1]

157)
all we know is that (-a,b) and (-b,a) are in the same quadrant...
but we dont know the actual sign of a or b..

but we can establish one thing ... that whatever the sign of a (i.e +ve or -ve), it will be the same for b, as they are in the same quadrant... else the points will not be in the same quadrant...

statement1)
xy> 0
does not say anything abt a & b
insufficient

statement 2)

ax> 0

since we dont the sign for y, we will get a yes and a no answer.....
insufficient...

together...

since ax>0
that means both are +ve or both are -ve
lets consider, if both are +ve

then since a is +ve, so b will also be +ve...
hence (-a,b) will lie in the second quadrant...

also since x will also be poistive...
and xy>0, so y will also be +ve
(-x,y) will be in the second quadrant...

u follow the same logic which considering a as -ve...

Hope this helps!!

[deepakteja1988]

159)
check the link below:
https://www.beatthegmat.com/xy-coordinate-t30811.html
also do a search before u post... u will find many posts answering the same question...

198) let the number of people at the beg = x
let the number of new clients acquired = a

number of clients at the end of the year = x + a

question asks the ratio of number of clients that Company X had at the end to no. of clients that Company X had at the beginning of the year
i.e (x + a )/x = 1 + a/x

so if we get a/x we can get our answer...

Statement 1) gives u x/a... which can be converted to a/x
sufficient

statement 2) does not give u info on the new clients...
insufficient...

Pick A

the word 'last year' in the options A and B, does it refer to the year the question is speaking about. I felt it the options were speaking about previous year as 'the year' was used in the question. Please let me know if there is something wrong in what i said.