Since we aren't told the number of people involved in the survey, let's make things easier on ourselves and assign a "nice" value to the number of people involved in the survey.
Let's say there were 100 people in the survey.

When we apply this to our table, we see that 35 people chose TV ads, 22 people chose coupons, 18 people chose store displays, and 15 people chose samples.

35 + 22 + 18 + 15 = 90
So, the table shows the results for 90 consumers

What fraction indicated either coupons or store displays?
Among the 90 consumers surveyed, 22 chose coupons, and 18 chose store displays
22 + 18 = 40
Fraction = 40/90
= 4/9

Answer: D

Cheers,
Brent
_________________

Solution

Given:

• The table shows partial results of a survey in which consumers were asked to indicate which one of six promotional techniques most influenced their decision to buy a new food product

To find:

• Out of those consumers who indicated one of the four techniques listed, what fraction indicated either coupons or store displays

Approach and Working:
If we assume the total number of consumers who responded is 100, then we can write:

• Total consumers responded to the four mentioned techniques = (35 + 22 + 18 + 15) = 90
• Total consumers responded to either coupons or store displays = (22 + 18) = 40
• Therefore, the required fraction = \(\frac{40}{90} = \frac{4}{9}\)

Hence, the correct answer is option D.

Answer: D
_________________

Notice that you are instructed to use the incomplete table; the percentages add up to only 90%. So first, you will add the percentages for “Coupons” and “Store Displays,” but then you must divide by the total of 90% to get the final answer, as shown here:

(22 + 18)/(35 + 22 + 18 + 15) = 40/90 = 4/9

Answer: D
_________________

When we add all the %'s we get 90 as total value

either coupons or store displays = 40/90

D
_________________

Why we should we add the other 10%?

Could anyone help explain why the stem says "or" "what fraction indicated either coupons or store displays" then we have a sum (22+18)? I think it should be 22/90 or 18/90.

(22+18)/90 --> stem should be "what fraction indicated coupons and store displays"
_________________

This question tries to trick you ! Otherwise the maths is pretty simple
You should solve 40/90 and not 40/100

If you found yourself bewildered why everyone is solving for 90% or why using 100 customers still means you use only the data available and solve for 90:

The question says "of the consumers who indicated one of the four techniques listed...". So, for example, rather than being able to use 22% (out of the usual 100%), the question wants you to use 22% out of the 90% that responded to one of these four options.

Using Brent's example, 100 total consumers, but 90 responded to one of the 4 so that's our denominator.


(Problem Solving Question 129 in GMAT 2021 guide)

Technique	Percent of consumers
Television ads	35%
Coupons	22%
Store displays	18%
Samples	15%
All 4 methods	90%

Given: The table shows partial results of a survey in which consumers were asked to indicate which one of six promotional techniques most influenced their decision to buy a new food product.
Asked: Of those consumers who indicated one of the four techniques listed, what fraction indicated either coupons or store displays?

The fraction indicated either coupons or store displays = (22%+18%)/90% = 40%/90% = 4/9

IMO D
_________________

Coupons + Store displays =22%+18%=40%

Total Survey \(= (35+22+18+15)\)%\(=90\)%

The fraction \(=\frac{40}{90}\)%=\(\frac{4}{9}\)

The answer is \(D\)
_________________

Answer: Option D

Video solution by GMATinsight



Get TOPICWISE: Concept Videos | Practice Qns 100+ | Official Qns 50+ | 100% Video solution CLICK HERE.
Two MUST join YouTube channels : GMATinsight (1000+ FREE Videos) and GMATclub
_________________

Video solution from Quant Reasoning:
Subscribe for more: https://www.youtube.com/QuantReasoning? ... irmation=1

_________________