Solution
Given:• All participants were asked two questions
• \(\frac{2}{3}\)rd of those surveyed responded “Strongly Agree” to the first question
• Of those responded to the first question, \(\frac{1}{5}\)th answered “Strongly Agree” to the second question
To find:• What portion of the survey participants did not answer “Strongly Agree” to both questions
Approach and Working: • We can assume the total participants is r.
o Participants who responded “Strongly Agree” to the 1st question = r * \(\frac{2}{3}\)
o Of those participants who responded “Strongly Agree” to the 1st question, participants who responded “Strongly Agree” to the 2st question = r * \(\frac{2}{3} * \frac{1}{5} = r * \frac{2}{15}\)
• Therefore, survey participants did not answer “Strongly Agree” to both questions = r – \(\frac{2}{15}r = \frac{13}{15}r\)
• Portion of survey participants did not answer “Strongly Agree” to both questions = \({(13/15r)}/r = \frac{13}{15}\)
Hence, the correct answer is option A.
Answer: ANote: rather than taking r as the total participants, if we assume the value of r as 15 or any multiples of 15 (because the lcm of denominators 3 and 5 is 15), the calculations will be much easier.