IR Questions: Multi Source Reasoning

Quarter Wit, Quarter WisdomNow that we have seen some basic Integrated Reasoning question types, let’s start working on tricky Integrated Reasoning questions. The first set we would like to discuss is from GMAT Prep Software’s practice questions. This question has elements of RC, CR, PS and DS, all combined in one!

It was one of the first IR questions I had come across and I thought to myself – GMAT just got more complicated! Not because the given information was hard to understand but because there was a lot of it which needed to be analyzed together to arrive at a conclusion – not unlike our real life situations.

Anyway, let’s take a close look at this set to get a feel of what official IR questions are like.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

From our discussion of the previous few weeks, it must be apparent that this is a multi source reasoning set. There are three tabs containing data about the techniques, artifacts and budget.

A quick read of the three tabs gives us the following general idea:

Techniques – Discusses techniques of dating different types of material

Artifacts – Discusses the collection of artifacts found and the accuracy of dating them

Budget – Discusses the cost of the techniques

In this way, we have got the lay of the land – so to speak. Now we can come back to the relevant information after reading the question.

Question 1: Which one of the following pieces of information would, on its own, provide the strongest evidence that the given artifact was actually produced on Kaxna?

(A)   A radiocarbon date of 1050 BC for a wooden bowl

(B)   IRMS analysis of a necklace made from animal bones and teeth.

(C)   A TL date for a fired-clay brick that places it definitively in the period of the Kaxna Kingdom

(D)   ICP-MS analysis of a metal tool that reveals element ratios unique to a mine on Kaxna

(E)    Determination that a stone statue was found near a quarry known to produce stone statues during the Kaxna Kingdom

Solution 1: The options give us various artifacts and ask us to find the one which has the strongest evidence of being produced on Kaxna. We would probably need the data given in the first two tabs – Techniques (to tell us which technique gives is what information about the artifact) and Artifacts (to tell us the accuracy of the techniques)

Let’s look at each option:

(A)   A radiocarbon date of 1050 BC for a wooden bowl

From tab 1, we know that radiocarbon dating gives us the approximate date of the plant’s death (and hence the approximate date of the creation of the object – within two years) but it doesn’t tell us the location of the creation of the object. We don’t know whether the bowl was made on the Kaxna islands.

(B)   IRMS analysis of a necklace made from animal bones and teeth.

IRMS analysis gives us clues about the animal’s diet and mineral content in water. Knowing these ratios for Kaxna island can give us an idea of whether the artifact was created on Kaxna. But this ratio of mineral content may not be unique to Kaxna and hence we cannot say whether the artifact was in fact created on Kaxna.

(C)   A TL date for a fired-clay brick that places it definitively in the period of the Kaxna Kingdom

TL dating may place the brick in the period of the Kaxna Kingdom but it doesn’t tell us the location where it was created. It may not have been created on the Kaxna island.

(D)   ICP-MS analysis of a metal tool that reveals element ratios unique to a mine on Kaxna.

ICP-MS analysis reveals ratios unique to a mine on Kaxna. This means the tool must have come from that mine on Kaxna. We can say with fair bit of certainty that the artifact came from Kaxna. Hence this seems to be the correct option. Let’s still take a look at option (E) too.

(E)    Determination that a stone statue was found near a quarry known to produce stone statues during the Kaxna Kingdom

Just because the stone statue was found near the quarry, it doesn’t mean that it was produced in the quarry. Hence we cannot say that the statue belongs to the Kaxna period.

Answer (D)

We need to understand the given data really well to be able to answer this question. Let’s look at another question which uses the third Tab now.

Question 2: For each of the following combinations of Kaxna artifacts, select Yes if, based on the information provided, the cost of all pertinent techniques described can be shown to be within the museum’s first-year Kaxna budget. Otherwise, select No.

Yes                 No

O                     O             2 bone implements and 5 fired-clay cups decorated with gold

O                     O             7 wooden statues and 20 metal implements

O                     O             15 wooden statues decorated with bone

Solution 2: This question is similar to the Two-Part Analysis questions we have seen before. You have to answer three parts correctly here to get the right answer.

To answer this one, we need the first and the third tabs – Techniques to match the artifacts with the technique and Budget to get the cost of the technique. Let’s find out.

Total Budget: Unlimited IRMS + $7000 (4TL + 15RC OR 40 ICP-MS)

Note that we have no idea about the costs of TL, RC, ICP-MS tests. We don’t know how their costs are related either.

1. 2 bone implements and 5 fired-clay cups decorated with gold

Bone implements need IRMS (unlimited available).

Fired clay objects need TL technique tests (5).

We know that $7000 is enough for 4 TL tests but we don’t know whether it is enough for 5 TL tests. E.g. each TL may cost $1500 or it may cost $150 – we don’t know. Hence, we cannot say that the cost is within the budget.

2. 7 wooden statues and 20 metal implements

Plant matter needs RC dating tests (7).

Metals need ICP-MS  tests (20).

We know that $7000 is enough for 40 ICP-MS tests so we know that 20 ICP-MS tests will cost less than or equal to $3500.

We also know that $7000 is enough for 4TL + 15RC tests which means $3500 is enough for 2TL + 7.5 RC tests. So we can be certain that $3500 is enough for 7 RC tests.

Therefore, the 7 RC tests and the 20 ICP-MC tests can be done within the $7000 budget.

3. 15 wooden statues decorated with bone

Plant matter needs RC dating tests (15)

Animal bones need IRMS tests which happen in-house.

We know that $7000 is enough for 4TL + 15RC tests which means it is certainly enough for 15RC tests.

Therefore, the 15 RC tests and 15 IRMS tests can be done within the $7000 budget.

So we will click on ‘No’ in the first row, ‘Yes’ in the second row and ‘Yes’ in the second row.

We hope you realize that IR questions may seem hard but when you get down to it, they are pretty much like the other question types with which we are already very familiar.

Karishma, a Computer Engineer with a keen interest in alternative Mathematical approaches, has mentored students in the continents of Asia, Europe and North America. She teaches the GMAT for Veritas Prep and regularly participates in content development projects such as this blog!

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