# Probability : Selection Without Replacement, Combinations and a Probability Tree

Three letters from A, B, C, D, and E are selected one at a time (without replacement).

a. What is the probability that they are selected in alphabetical order?

b. What is the probability that they are selected in alphabetical order, if B is the first letter selected.

https://brainmass.com/math/probability/selection-without-replacement-combinations-probability-tree-44204

#### Solution Summary

Combinations and a probability tree are used to solve a 'selection without replacement' probability problem. The solution is detailed and well presented.

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