Ratios - recipe

[Xbond]

Hi there,

What is the concept of this DS ?

Malik’s recipe for 4 servings of a certain dish requires 1½ cups of pasta. According to the recipe, what is the number of cups of pasta that Malik will use the next time he prepares the dish?

(1) The next time he prepares the dish, Malik will make half as many servings as he did the last time he prepares the dish.

(2) Malik used 6 cups of pasta the last time he prepared the dish.

I answered A but the right answer is C

[raleigh]

It's a "can you determine the value for..." problem?

(1) You have no idea how much he made last time so you cannot get the amount down. If he used 10 cups of pasta last time, the answer will be 5. If he used 6 cups of pasta last time, the answer will be 3. This is insufficient.

(2) There is no information that says he will not make 1 cup of pasta, 2 cups of pasta, 3 cups of pasta,... the next time he makes pasta. This is insufficient.

(1)+(2) (2) tells us that last time he made 6 cups of pasta. (1) tells us that he will cook half as much (3 cups) next time he makes pasta. So you can determine the specific value. This is sufficient. The answer is C.

[Xbond]

Many thks