Seven numbers are arranged in increasing order. Their median is 18. If the 4th number is increased by 6 and the 1st number is decreased by 6, what is the new median?

For 7 sorted numbers, the median is the 4th term = 18. Increasing the 4th term by 6 makes it 24 (it stays the largest among the first four and is still the central term). Changing the 1st term does not affect the middle position. New median = 18 + 6 = 24.