For a set of five whole numbers, the mean is 4, the mode is 1, and the median is 5. What are the five numbers?

SO we need 5 numbers that equal to 20, with 5 being the middle number, and ones being the most used number so

1 1 5 x y

According to this, x and y must equal 13 and both be bigger then 5. Because we can rule out every other number, x and y must be 6 and 7.

Your 5 numbers are 1, 1, 5, 6, 7.