This question was asked in Misc 17

A firm which involves in the production of tea and coffee of a particular kind conduct a survey on the group of 600people they found that 150 people like tea and 225 like coffee of that kind and 100 people like both the tea and coffee and remaining the people like the other usual drinks find how many people neither like tea nor coffee of that kind ?what was the motive/action behind this survey ?

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