Question 14 (10310): Problem Solving, Online Exclusive: GMAT™ Official Guide 2023-2024: Online Question Bank.
Question 1 (PS01301.02): GMAT Online Question Bank (GMAT Official Guide 2021 and beyond)
Video explanation: A marketing firm determined that, of 200 households…
2017 OG
Diagonistic PS
Q:6
Can you please explain the line, ‘for every household that used both brands of soap, 3 used only brand B soap’
They are giving you a ratio between the two quantities. So if x households used both brands of soap, this is the overlap region in the typical two category Venn diagram, then the number of households that use only brand B soap is 3x. The region of households that use brand B soap only is the region left if you took out the households that use both brand A and brand B soap. It is best to visualize this by categorizing the regions in Venn diagram.