Question

In a market survey, 20% opted for product $A$, 60% for $B$, and the rest were uncertain. If the difference between those who opted for $B$ and those uncertain is $720$, how many individuals were surveyed?

• A. 1440
• B. 1800
• C. 3600
• D. Data inadequate

Hint:

Translate verbal percent gaps into a single net percent and equate it to the given difference to find the total.

Answer 1

The Correct Option is B

Uncertain $=100\%-20\%-60\%=20\%$.
Difference $=60\%-20\%=40\%$ of the total.
So $0.40\times N=720 \Rightarrow N=\dfrac{720}{0.40}= \boxed{1800}$.