The sum of income of A and B is more than that of C and D taken together. The sum of income of A and C is the same as that of B and D taken together. Moreover, A earns half as much as the sum of the income of B and D. Whose income is the highest?

Four tests—Physics, Chemistry, Mathematics and Biology are to be conducted on four consecutive days, not necessarily in the same order. The Physics test is held before the test which is conducted after Biology. Chemistry is conducted exactly after two tests are held. Which is the last test held?

If there is a policy that 1/3rd of population of a community has migrated every year from one place, to some other place, what is the leftover population of that community after the sixth year, if there is no further growth in the population during this period?

If second and fourth Saturdays and ,all the Sundays are taken as only holidays for an office, what would be the minimum number of possible working days of any month of any year?

With reference to the above information, consider the following statement

1. Some supporters of 'party X' knew Z

2. Some supporters of 'party X', who opposed Z's campaign strategy, knew Z.

3. No supporters of 'party X' supported Z's campaign strategy.

Which of the statements given above, is/are not correct?

With reference to the above information, which one among the following statements must be true?