The graph is part of a report about land use in a certain region

Question

https://gmatclub.com/forum/download/file.php?id=85287 The graph is part of a report about land use in a certain region. The chart shows, for each of the designations park and vacant, the percent of the region's total area that has that designation and the percent of the total number of lots in the region that have that designation. All land in the region is divided into lots. Select the options from the drop-down menus that complete the statement so that it most accurately reflects the information provided. For this region, the ratio of the number of lots with the designation vacant to the number with the designation park is approximately GRAPH_1_PLACEHOLDER For this region, the ratio of the mean area of the lots with the designation vacant to the mean area of the lots with the designation park is approximately GRAPH_2_PLACEHOLDER ID: 102501 GMAT-Club-Forum-krzyv2tm.png GMAT-Club-Forum-nm5sr0fq.png

cheshire · Accepted Answer

OA:

Question 1:  
The graph indicates that for this region approximately 20% of the lots have the designation vacant and 2% of the lots have the designation park. Therefore, for this region the number of lots with the designation vacant \s 10 times the number with the designation park, and hence for this region the ratio of the number of lots with the designation vacant to the number with the designation park is 10 to 1.

The correct answer is 10 to 1.

Question 2:  
Let 4 be the total area of the region and let N be the total number of lots in the region. The graph shows that there are approximately 0.2N (i.e., 20% of N) lots with the designation vacant and these lots together use an area of approximately 0.1A (i.e., 10% of A). Thus, the mean area of the lots with the designation vacant is approximately  \frac{01A}{02N} =\frac{1}{2} (\frac{A}{N})  The graph also shows that there are approximately 0.02N (i.e., 2% of N) lots with the designation park and these lots together use an area of approximately 0.4/4 (i.e., 40% of A). Thus, the mean area of the lots with the designation park is approximately  \frac{0.4A}{0.02N} = 20(\frac{A}{N})  Therefore, for this region the ratio of the mean area of the lots with the designation vacant to the mean area of the lots with the designation park is approximately 1/2 to 20, or equivalently, 1 to 40.

The correct answer is 1 to 40.

BinodBhai · Answer

This is a very tricky question, esp the 2nd part.. You need to read the stem carefully

Mean area = Area / # of lots 
Let total area and total lots = 100 each

For Park:
Total Area = 40% = 40
Total lots = 2% = 2
Mean Area of lots = 40/2 = 20

For Vacant:
Total Area = 10% = 10
Total lots = 20% = 20
Mean Area lots = 10/20 = 1/2

Required ratio: Vacant / Park = 1/2 / 20 = 1/40

adityaprateek15 · Answer

cheshire  Could you please share the OA? Thanks.

melodicschool · Answer

please explain 2nd part

thesarkars · Answer

Hi, can you post the OA please?

poojaarora1818 · Answer

Solution:

Dropdown 1 For this region, the ratio of the number of lots with the designation vacant to the number with the designation park is approximately 10:1.

Number of lots with the designation vacant 0-5, 5-10, 10-15, 15-20--> 20

Number of lots with the designation park 0-2--->2

So, the ratio would be  \frac{20}{2}  = 10:1

Dropdown 2 For this region, the ratio of the mean area of the lots with the designation vacant to the mean area of the lots with the designation park is approximately 4:1.

Mean area of the lots with the designation park= \frac{0+5+10+15+20+25+30+35+40}{900}  =  \frac{1}{5} .

Mean area of the lots with the designation vacant = \frac{0+5+10}{300} = \frac{1}{20}

So, the ratio should be 4:1.

bbb1923 · Answer

different from oa

cheshire · Answer

Thank you OA has been fixed

DhanyaAbhirami · Answer

Number of lots = Total Area/Mean Lot Area

Ratio of number of vacant lots to park lots = (percent lots vacant) / (percent lots park) = 20/2 = 10:1

Ratio of mean lot area vacant to mean lot area park = (percent area vacant / percent lots vacant) / (percent area park / percent lots park) = (10/20)/(40/2) = 1 : 40

tryorcry · Answer

1 is simple.
For 2, 
total area = N
Vacant mean area = total area / lots = 0.1N/20-------A
Park mean area= 0.4N/2--------------B
A/B=1/40

The graph is part of a report about land use in a certain region

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The graph is part of a report about land use in a certain region

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