In a certain drink, the ratio of vodka to orange juice is 2 : 3, and

This is a fairly straightforward problem where you have to combine two ratios to obtain a new ratio. If you have practiced sufficient problems on this concept, this question is actually an easy question.

Ratio of Vodka to orange juice = 2:3; ratio of orange juice to tonic water = 2:1.
To combine the two ratios, multiply the first ratio by 2 and the second ratio by 3. On doing this, we get,
Ratio of Vodka to orange juice to tonic water = 4:6:3.

Let us assume that there are 4 ounces of Vodka, 6 ounces of orange juice and 3 ounces of tonic water.
Now, if 3 more ounces of tonic water are added to the drink, we will have 6 ounces of tonic water. This makes the ratio of orange juice to tonic water 1:1. But the proportions cannot be changed, as per the question. So, we need to add 6 more ounces of orange juice to maintain the original ratio of 2:1.

Using a similar analogy, it is not difficult to understand that, for 12 ounces of orange juice (remember you added 6 more to the original 6), there needs to be 8 ounces of vodka to maintain the ratio of 2:3. But we only had 4 ounces originally; this means we have to add 4 more ounces to maintain the final ratio of 4:6:3.

After all the additions, let’s see what we have:
4 + 4 = 8 ounces of Vodka
6 + 6 = 12 ounces of orange juice
3 + 3 = 6 ounces of tonic water.
The numbers 8, 12 and 6 are definitely in the ratio of 4:6:3. This is a very simple way of verifying the answer that we got.

So, the correct answer option is C.

A couple of things to note about ratio questions. One – always take simple values to mirror the ratio given, instead of taking variables. Two – always verify your answers by checking if it satisfies the ratio provided. Also remember that ratio questions are best suited to be solved using answer options, so, employing methods like elimination and back solving will save time and energy.

Hope this helps!
Arvind,
CrackVerbal PrepTeam