A diary, a calendar and a planner are all tools used to record dates, appointments and daily schedules, so they belong to the same group. A purse is used to carry money and does not track time, which makes it the odd one out.
Since only the purse fails to keep track of dates and schedules, the answer is purse.
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?