Bounds for Coffee and Tea Drinkers

A survey asked 100 respondents two questions:

1. Do you like tea?
2. Do you like coffee?

70% of respondents said they liked coffee, and 80% of the respondents said they liked tea. Only 10% of respondents said they liked neither.

Based on this survey, what are the upper and lower bounds for the proportion of the population that like tea and coffee?