3. a. In a survey of 400 people, 300 people drink only one drink out of tea and coffee.
50 people drink none of them.
i.
Find the number of people who drink both drinks.
ii. Find the percentage of people who drink both drinks.
iii. If 200 people drink coffee only, how many people drink tea?
iv. Find the ratio of the number of people who drink both drinks and only one
drink.
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