Self doubt on probability

Question

An element is to be inserted in an array and the probability that it has been entered correctly is 0.9. Find the probability that the sorting algorithm worked correctly.
How to solve this type of questions?

Answer 1

$\because$  It is given that we just have to insert 1 element in an array.

So $2$ cases arise

case 1.

The element is inserted at correct position. This means that the sorting algorithm worked correctly.

case 2.

The element is inserted at wrong position. This means that the sorting algorithm worked incorrectly.

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So , we can say that the probability that the sorting algorithm worked correctly

= Probability of inserting the element at correct position

= $0.9$