Data Sufficiency

Hi there,

I would like to know the simplest process to resolve this DS. Explanation is requested.

A contractor combined x tons of a gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G by weight. What is the value of x ?

(1) y = 10
(2) z = 16

E?

IMO C
the equation you get is

.1X+.02Y=.05Z
we need both Y and Z to get X

hence C

tohellandback wrote:IMO C
the equation you get is

.1X+.02Y=.05Z
we need both Y and Z to get X

hence C

.1X + .02Y=.05(X+Y)

since Z is made up of both X and Y
or this thing we cnt assume????

If we follow the above equation the answer is D

ankit1383 wrote:

tohellandback wrote:IMO C
the equation you get is

.1X+.02Y=.05Z
we need both Y and Z to get X

hence C

.1X + .02Y=.05(X+Y)

since Z is made up of both X and Y
or this thing we cnt assume????

If we follow the above equation the answer is D

thanks. you are right. I missed that.
answer must be D

how do you find the value of x with statement 2 in order to say D is right answer :

.1X + .02Y=.05(X+Y)
.1X + .02Y=.05(Z)
.1X + .02Y=.05(16)
.1X + .02Y=8

at the end you have 2 differents variables except whether you assume X+Y =8+8, no ?

how do you find the value of x with statement 2 in order to say D is right answer :

.1X + .02Y=.05(X+Y)
.1X + .02Y=.05(Z)
.1X + .02Y=.05(16)
.1X + .02Y=8

at the end you have 2 differents variables except whether you assume X+Y =8+8, no ?

Xbond,

can't Y be equal to 1-X?

Y is Z-X

So you have 2 eqns and 2 variables

many thks guys

OA is D

Yes, Y is simply Z - X.

If we replace Y with Z - X in the equation, we get:

.10X + .02(16 - X) = .8

X = 6