Question

Soda ash (sodium carbonate) is made in two ways: from natural trona ore (natural soda ash), and from common salt by the Solvay process (synthetic soda ash). Tata Chemicals is one of the world's largest soda ash producers.

Two charts give the data. The first chart plots WORLD production of natural and synthetic soda ash for the years 2001 to 2006: the synthetic soda ash bars climb every year over this period, while the natural soda ash bars stay roughly flat. The second chart plots Tata Chemicals' own natural and synthetic output:

Year	Natural Soda Ash (MT)	Synthetic Soda Ash (MT)
2005	0	0.7
2007	0.4	2.2
2008	3.2	2.2

Which of the following statements are true?
1. Proportion of natural soda ash to synthetic soda ash has decreased from 2001 to 2006 globally.
2. Proportion of natural soda ash to synthetic soda ash has increased from 2001 to 2006 globally.
3. Proportion of synthetic soda ash to total soda ash has decreased for Tata Chemicals from 2005 to 2007.
4. Proportion of synthetic soda ash to total ash has increased for Tata Chemicals.

• A. 1 and 3
• B. 1 and 4
• C. 2 and 4
• D. 2 and 3

Hint:

Look at which bar is climbing and which is flat in each chart: a ratio falls whenever its denominator grows faster than its numerator.

Answer 1

The Correct Option is A

This question bundles two separate true or false checks: a world level trend (statements 1 and 2) and a Tata specific trend (statements 3 and 4).

1. Statement 1 (world natural to synthetic ratio fell, 2001 to 2006): the synthetic bars rise every year in the world chart while the natural bars barely move, so natural's share relative to synthetic keeps shrinking. This is true.
2. Statement 2 (world ratio rose): this is the opposite of what the chart shows, so it is false.
3. Statement 3 (Tata's synthetic share of its own output fell, 2005 to 2007): Tata made no natural soda ash in 2005, so its synthetic share that year was $0.7/0.7 = 100$ percent. By 2007, with 0.4 MT natural added, synthetic's share dropped to $2.2/2.6 \approx 85$ percent. Since 85 is less than 100, the share fell. This is true.
4. Statement 4 (Tata's synthetic share rose): we just showed the share fell from 100 percent down toward 85 percent and then about 41 percent by 2008, so it cannot have risen too. This is false.

Pairing the one correct world statement (1) with the one correct Tata statement (3) gives the answer.

Let's summarize:

• World synthetic soda ash output grew steadily from 2001 to 2006 while natural output stayed flat, so natural's share fell.
• Tata's synthetic share fell from 100 percent in 2005 to about 85 percent in 2007 as its natural output came online.

So the correct combination is statements 1 and 3, which is option A.