Food -- Number of Calories per Kilogram -- Number of Grams of Protein per Kilogram
S ----- 2.000 -----------------------------------------150
T ----- 1,500 -----------------------------------------90

The table above gives the number of calories and grams of protein per kilogram of foods S and T. If a total of 7 kilograms of S and T are combined to make a certain food mixture, how many kilograms of food S are in the mixture?

(1) The mixture has a total of 12,000 calories --> say x kilograms of food S are in the mixture then there will be 7-x kilograms of food T in the mixture. Now, according to the table above we'll have: 2,000x+1,500(7-x)=12,000, since there is only one variable then we can solve for it. Sufficient.

(2) The mixture has a total of 810 grams of protein --> 150x+90(7-x)=810, since there is only one variable then we can solve for it. Sufficient.

Answer: D.
_________________

Responding to a pm:

S -> 2000 C/kg and 150 P/kg
T -> 1500 C/kg and 90 P/kg

The mixture of the two is 7 kg.

Statement 1:
Mixture has 12000 C i.e. 12000/7 C/kg

The average calorie content of the mixture is 12000/7.

wT/wS = (AS - Aavg)/(Aavg - AT) (this formula represents the scale. You can either use the number line or this formula)

wT/wS = (2000 - 12000/7)/(12000/7 - 1500) = 2000/1500 = 4/3
So, in 7 kg, T was 4 kg and S was 3 kg

You don't really need to solve it. From the data you see that you have calorie content of each food and the average calorie content, so you can easily find the ratio of each food in the mixture. You also have the amount of mixture so you can easily find the amount of each food in the mixture.

Statement 2:
Mixture has 810 gms of P i.e. 810/7 P/kg

wT/wS = (150 - 810/7)/(810/7 - 90)

Again, same process as above.
_________________

Bunuel/ Karishma
Please let me know if this approach is ok
stmt 1
s+t = 7
2000s+1500T= 12000
solving for s , we get s is 3 and therefore sufficient

similiarly
s+t =7
150s +90 T= 810, solving for s, we get s = 3 and hence sufficient.

Your solution is correct. Notice that it's basically the same as my solution here: the-table-above-gives-the-number-of-calories-and-grams-of-129998.html#p1068312 You used two variables s and t (7-s), while I used x and 7-x.
_________________

Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE


_________________

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________