unraveled
The inventory of grape jelly on a store's shelves consists only of 2-ounce, 6-ounce, and 16-ounce jars. If the average jar size of the current inventory is 6.4 ounces, how many additional 2-ounce jars must be put on the shelves to reduce the average size to 6.0 ounces?
(1) The current ratio of 2-ounce to 6-ounce to 16-ounce jars is 15:27:8.
Theres is a relation between the three so we can find the common factor x in all of them as in if 15x, 27x and 8x are number of jars of 2-ounce, 6-ounce and 16-ounce jars respectively. Hence we can find the value of more 2-ounce that needs to be added by keeping other ones same so that avergae comes down to 6.
\(\frac{(15x * 2 + 27x*6 + 8x*16) }{ (15x + 27x + 8x)}\) = 6.4
Once x(here 1) is known we can add the another vaiable to 15x and do the same calculation as above to find that variable.
SUFFICIENT.
(2) There are initially 7 more 2-ounce jars than 16-ounce jars.
Here's a catch. We may initially choose to eliminate this but this statement creates a boundation that eventually gives us get the answer.
Taking a clue from the Statement 1, we can be sure that the number of 2-ounce and 16-ounce jars can only be 15 and 8
Answer D.
According to me,
The equation you mentioned (\(\frac{(15x * 2 + 27x*6 + 8x*16) }{ (15x + 27x + 8x)}\) = 6.4) can not be solved, as x will cancel out itself from the numerator and the denominator.
So, St.1 alone is not sufficient. Hence Eleminating A & D.
For St.2,
To justify St.2, we CANNOT take any clues from st.1, and as st.2 in this case alone is not sufficient, we can eliminate it.
Hence, eliminating B.
Of course, now if we consider both statements together, we can easily get the value of x and hence the required answer.
So the correct answer choice will be C.
Correct me if required. Thanks.