A professor, a lecturer and a teacher all give academic instruction in a school, college or university, so they share the same profession of formal teaching. A preacher delivers religious sermons in a place of worship, which is a different kind of work.
The role that does not fit the academic teaching group is the preacher.
Three of the following four items are alike in a certain way and can be grouped together. Which item cannot be grouped with the other three?
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?