Excel to return a value in a cell after checking a range of cells

Question

In Excel I have a range of cells; for simplicity say three columns A1:A3 containing either the letter P, M or D. I would like to be able to check this range of cells and display in cell A4 either P, M or D depending on the frequency of the letters (see below for example of intended results). Need all cells as D to result in D. Its to track student grades, Pass (lowest denominator), Merit and Distinction.

PPP = P; PMP = P; MPP = P; PPM = P; MMM = M; MDD = M; MMD = M; DMM = M; DDD = D; PMD = P

Answer 1

Use this:

=IF(COUNTIF(A1:A3,"P"),"P",IF(COUNTIF(A1:A3,"M"),"M","D"))