An apple farm installed a fish pond on its land to save money and

Question 1 - Looking at the graph, the cost of fertilizer in year 1 was 0.05 dollars per 10 kg apples sold. In year 5, that number was 0.005. You could calculate the decrease each year in between and get an average, but just by looking at the graph, we can see we're dealing in hundredths. Therefore the answer is D. 0.01

I think they're trying to throw you off by having you pull numbers for fertilizer cost from the right hand "dollars per 10kg of apples sold" side of the graph.

Question 2. - On the graph, the total number of fish sold in year 3 was 2,000 and the total in year 4 was 3,000, an increase of 1,000 fish. However, from year 4 (total fish 3,000) to year 5 (total fish 3,500), the increase is only 500 fish. Since we're talking about rate, an increase of 1,000 in a one year period, then an increase of only 500 the following year means that the rate is decreasing. Answer: B decreasing.

Can be a bit tricky if you only look at the black line as increasing, rather than comparing the rate of change.

The “Power of 10” is any of the integer exponents of the number 10. In other words, the number of 10s indicated by the exponent, multiplied together.

For example: 10 to the 3rd power is 10 x 10 X 10 = 1,000.

If the exponent is greater than zero, written in long form, a power of 10 is the number 1 followed by n zeros. N being the exponent.
Example: \(10^8\) equals 1 with 8 zeros behind it --> 100,000,000

If the exponent is less than zero, written out, the power of 10 is 1 with n places after the decimal point. N again being the exponent.
Example: \(10^{-3}\) is 1 with three places after the decimal point --> 0.001

In this particular problem, they are asking you to find the answer “to the nearest power of ten” because all of the answer choices are listed in powers of ten. By looking at the graph, we see that in year 1, the cost of fertilizer (per 10 kg of apples) is 0.05 and in year 5, the cost is 0.005. To calculate the actual average, first get the total difference

0.05 – 0.005 = 0.045

And divide it by the number of years

0.045 / 5 = 0.009

So, 0.009 is the true average, but the question asks you to find the average to the nearest power of 10. 0.009 is not a power of 10, so we need to round up a bit. Hence, 0.01 is the answer.

That’s the very long answer. The short answer is, because this is an integrated reasoning question, they probably just want to make sure you can read a graph correctly. The trick is not to focus on the actual average (doing the exact math to calculate 0.009), but to look at the graph and estimate by about how much the cost is decreasing per year. The cost of fertilizer per 10 kg of apples sold is listed on the right-hand side of the graph. Over 5 years, each year, the cost seems to go down by about 0.01 dollars.

1) D -0.01 since the change from 0.005 to 0.05
2) The rate of increase is decreasing from 3-4 and from 4-5

Posted from my mobile device

According to my understanding,
The answer to question 1 should be option D, as the average of the decrease of the amount by which the cost of fertilizer per 10 kg of apples sold to the nearest power of 10 would be 0.01. Someone can try to calculate the value(I partially did it and on seeing the option knew D was the answer) or someone can just scan the graph look at the answer options and choose D to be the answer.

The answer to question 2 should be option B i.e. decreasing, as from year 3 to year 4 the number of fish sold does increase but from year 4 to year 5, the value decreases.

Hey there guys,

Could anyone please explain me what the phrase "the nearest power of 10" means?

Just curious, what if one where asked to solve for the average amount by which the cost of fertilizer per 10 kg of apples sold decreased from year 1 to year 5?

amount by which the cost of fertilizer per 10 kg of apples sold decreased from year 1 to year 5 = .05 - .005 = .045

divide by five to get average amount by which the cost of fertilizer per 10 kg of apples sold decreased from year 1 to year 5 so 0.045/5=.009.

do folks agree? I find it helpful to solve problems such as these then compare to answer choices

The combo chart is misleading I think. GMAC should have used 2 separate charts instead for better readability.

mborski

What the 5 observations of the difference for which you are calculating the average of the 5 years?

Rytthhm short video solution here (2:08):

Sajjad1994 I saw this one in OG 2023-2024, do you want to re-tag the source? It says "GMAT Pill" now. Thanks!

GMATCoachBen shuld we not divide the change over the 5 years by 4 and not 5 since we have 4 values?

Elite097 Yes, you are correct! I mentioned in the video that there are 4 decreases (year 1 to 2, year 2 to 3, year 3 to 4, and year 4 to 5).

However, it makes no difference here, since the answers are so spread out. It's very helpful to round and approximate when we see that the answers are spread out, or when the stem says "nearest to" or "approximately"!